The effect of intermittent compared with continuous energy restriction on glycaemic control in patients with type 2 diabetes: 24-month follow-up of a randomised noninferiority trial

The impact of food-based dietary strategies on achieving type 2 diabetes remission: A systematic review

OBJECTIVE

Conventional wisdom once asserted that diabetes was irreversible. However, contemporary research indicates that dietary changes may contribute to achieving diabetes remission in persons with type 2 diabetes (T2D). We aimed to determine the effectiveness of food-based dietary approaches for T2D remission.

METHODS

We systematically searched Medline, EMBASE, and Web of Science, along with exploring grey literature, to identify longitudinal studies. Data extraction and quality assessment adhered to predetermined criteria, and the results of the included studies were analyzed using a narrative synthesis and graphical display.

RESULTS

We included 52 original studies-40 % were rated as low-risk of bias. Overall, studies showed the low-carbohydrate Mediterranean diet (LCMD), compared to a low-fat diet, was more effective for achieving T2D remission in newly diagnosed patients who also had a weight loss of up to 6 kg. Compared to both the traditional Mediterranean diet and the American Diabetic Association diet, the LCMD was also more effective at diabetes remission for persons with T2D with any duration of diabetes; however, more substantial weight loss of 8 kg was required. Other diets that appeared effective for T2D remission included low-calorie diets and diets high in plant protein sources. Less weight loss was needed to achieve remission on plant-based diets than a low-calorie diet and low-carbohydrate diet.

CONCLUSIONS

Diets high in plant protein sources may support T2D remission, particularly among newly diagnosed patients. For patients with a duration of over 2 years, the combination of plant-based diets with greater weight loss should be considered to induce remission.

Behavioral Lifestyle Interventions for Weight Loss in Overweight or Obese Patients with Type 2 Diabetes: A Systematic Review of the Literature

PURPOSE OF REVIEW

Around 80-90% of patients with type 2 diabetes mellitus (T2DM) are overweight or obese, presenting a greater risk for serious health complications and mortality. Thus, weight loss represents a main goal for T2DM management. Although behavioral lifestyle interventions (BLIs) could help promoting weight loss in T2DM patients with overweight or obesity, their effectiveness is still controversial. This systematic review offers an updated and comprehensive picture of BLIs according to Michie's classification in T2DM patients with overweight or obesity and identifies possible factors (related to both patients and interventions) associated with weight loss. The PRISMA guidelines were followed. The literature search till March 2023 indicated 31 studies involving 42 different BLIs.

RECENT FINDINGS

Our findings suggest that structured BLIs, characterized by frequent feedback and support, can lead to a clinically meaningful 5% weight loss, regardless of specific behavioral, diet, and physical activity components. Further research should address methodological issues and heterogeneity of interventions, also considering the effect of pharmacological therapies on weight reduction. Lastly, more attention should be paid to the long-term effectiveness of behavioral lifestyle interventions and to the relationship between weight loss and diabetes.

The effectiveness of mobile app usage in facilitating weight loss: An observational study

Aim

With increasing rates of global obesity and associated health issues, there is an ever-increasing need for weight management solutions to be more accessible. Mobile applications offer accessible support systems and have the potential to offer a viable and effective weight management solution as an alternative to traditional healthcare models.

Objective

To evaluate the effectiveness of the SIMPLE mobile application for time-restricted eating in achieving weight loss (WL).

Methods

User data were analyzed between January 2021 and January 2023. In-app activity was calculated as the proportion of active days over 12, 26 and 52 weeks. A day is considered active if it contains at least one in-app action (e.g., logging weight, food, fasting, or physical activity). Users were categorized into four in-app activity levels: inactive (in-app activity <33%), medium activity (33%-66%), high activity (66%-99%), and maximal activity (100%). Weight change among in-app activity groups was assessed at 12, 26, and 52 weeks.

Results

Out of 53,482 users, a positive association was found between the use of the SIMPLE app and WL. Active app users lost more weight than their less active counterparts. Active users had a median WL of 4.20%, 5.04%, and 3.86% at 12, 26, and 52 weeks, respectively. A larger percentage of active users-up to 50.26%-achieved clinically significant WL (≥5%) when compared to inactive users. A dose-response relationship between WL and app usage was found after adjusting for gender, age, and initial Body Mass Index; a 10% increase in app activity correlated with increased WL by 0.43, 0.66 and 0.69 kg at 12, 26, and 52 weeks, respectively.

Conclusions

The study demonstrates that the SIMPLE app enables effective WL directly associated with the level of app engagement. Mobile health applications offer an accessible and effective weight management solution and should be considered when supporting adults to lose weight.

Effect of 5:2 Regimens: Energy-Restricted Diet or Low-Volume High-Intensity Interval Training Combined With Resistance Exercise on Glycemic Control and Cardiometabolic Health in Adults With Overweight/Obesity and Type 2 Diabetes: A Three-Arm Randomized Controlled Trial

OBJECTIVE

We aimed to examine the effects of a 5:2 diet (2 days per week of energy restriction by formula diet) or an exercise (2 days per week of high-intensity interval training and resistance training) intervention compared with routine lifestyle education (control) on glycemic control and cardiometabolic health among adults with overweight/obesity and type 2 diabetes.

RESEARCH DESIGN AND METHODS

This two-center, open-label, three-arm, parallel-group, randomized controlled trial recruited 326 participants with overweight/obesity and type 2 diabetes and randomized them into 12 weeks of diet intervention (n = 109), exercise intervention (n = 108), or lifestyle education (control) (n = 109). The primary outcome was the change of glycemic control measured as glycated hemoglobin (HbA1c) between the diet or exercise intervention groups and the control group after the 12-week intervention.

RESULTS

The diet intervention significantly reduced HbA1c level (%) after the 12-week intervention (-0.72, 95% CI -0.95 to -0.48) compared with the control group (-0.37, 95% CI -0.60 to -0.15) (diet vs. control -0.34, 95% CI -0.58 to -0.11, P = 0.007). The reduction in HbA1c level in the exercise intervention group (-0.46, 95% CI -0.70 to -0.23) did not significantly differ from the control group (exercise vs. control -0.09, 95% CI -0.32 to 0.15, P = 0.47). The exercise intervention group was superior in maintaining lean body mass. Both diet and exercise interventions induced improvements in adiposity and hepatic steatosis.

CONCLUSIONS

These findings suggest that the medically supervised 5:2 energy-restricted diet could provide an alternative strategy for improving glycemic control and that the exercise regimen could improve body composition, although it inadequately improved glycemic control.

The Effect of a Combined Intermittent Fasting Healthy Plate Intervention on Anthropometric Outcomes and Body Composition Among Adults With Overweight and Obesity: Nonrandomized Controlled Trial

BACKGROUND

Adult obesity and overweight pose a substantial risk to global public health and are associated with various noncommunicable diseases. Although intermittent fasting (IF) is increasingly used as a relatively new dietary strategy for weight loss, the effectiveness of 2 days per week of dry fasting remains unknown.

OBJECTIVE

This study aims to evaluate the effectiveness of a combined dry IF and healthy plate (IFHP) and healthy plate (HP) intervention in improving anthropometric outcomes and body composition.

METHODS

This nonrandomized controlled trial involved 177 adults who were overweight and obese. Among them, 91 (51.4%) were allocated to the IFHP group and 86 (48.6%) were allocated to the HP group. The overall study duration was 6 months (October 2020 to March 2021). The intervention was divided into 2 phases: supervised (3 months) and unsupervised (3 months). The data were collected at baseline, after the supervised phase (month 3), and after the unsupervised phase (month 6). Anthropometric (weight, height, waist circumference, and hip circumference) and body composition (body fat percentage, body fat mass, skeletal muscle mass, and visceral fat area) data were measured at all 3 data collection points. Sociodemographic data were obtained using a questionnaire at baseline.

RESULTS

Most participants were female (147/177, 83.1%) and Malay (141/177, 79.7%). After 3 months, there were significant reductions in weight (difference -1.68; P<.001), BMI (difference -0.62; P<.001), body fat percentage (difference -0.921; P<.001), body fat mass (difference -1.28; P<.001), and visceral fat area (difference -4.227; P=.008) in the IFHP group, whereas no significant changes were observed in the HP group. Compared to baseline, participants in the IFHP group showed a significant decrease in weight (difference -1.428; P=.003), BMI (difference -0.522; P=.005), body fat percentage (difference -1.591; P<.001), body fat mass (difference -1.501; P<.001), visceral fat area (difference -7.130; P<.001), waist circumference (difference -2.304; P=.001), and hip circumference (difference -1.908; P=.002) at month 6. During the unsupervised phase, waist (IFHP difference -3.206; P<.001, HP difference -2.675; P=.004) and hip (IFHP difference -2.443; P<.001; HP difference -2.896; P<.001) circumferences were significantly reduced in both groups (P<.01), whereas skeletal muscle mass (difference 0.208; P=.04) and visceral fat area (difference -2.903; P=.003) were significantly improved in the IFHP group only. No significant difference in the between-group comparison was detected throughout the intervention (all P>.05).

CONCLUSIONS

A combined IFHP intervention was effective in improving anthropometric outcomes and body composition in adults with overweight and obesity.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/33801.

Chrononutrition in the Prevention and Management of Metabolic Disorders: A Literature Review

BACKGROUND

The concept of time-restricted eating (TRE) or time-restricted feeding (TRF) promotes daily periods of feeding and fasting to determine whole-body physiology. Chronic misalignment of circadian rhythms or chrono-disruption is related to an increased risk of diverse metabolic disorders. The progression of non-communicable diseases seems to be affected by the timing of meals. As a result, intermittent fasting is a promising approach for their management. The aim of the present literature review is to examine and scrutinize the TRE protocols in the fields of prevention and management of metabolic disorders.

METHODS

This is a thorough literature review of the reported associations among circadian rhythm, metabolic disorders, diabetes mellitus, obesity, TRE, TRF, dietary habits, circadian disruption, cardiovascular diseases, atherosclerosis, and non-alcoholic fatty liver to find the already existing clinical studies from the last decade (2014-2024) in the most precise scientific online databases, using relevant specific keywords. Several inclusion and exclusion criteria were applied to scrutinize only longitudinal, cross-sectional, descriptive, and prospective clinical human studies.

RESULTS

The currently available clinical findings remain scarce and suggest that chrononutrition behaviors such as TRE or TRF may promote several metabolic benefits, mainly in body weight control and fat loss. Improvements in glucose levels and lipid profiles are currently quite controversial since some clinical studies show little or no effect. As far as liver diseases are concerned, the efficacy of intermittent fasting seems to be stronger in the management of non-alcoholic fatty liver disease due to body weight decline and fat loss.

CONCLUSIONS

Even if there has been a gradual increase in clinical studies in the last few years, providing promising perspectives, currently, there is no conclusive evidence for the role of chrononutrition in metabolic disorders. Future studies should be well-designed with longer duration and larger sample sizes. Moreover, it is important to examine the best timing of the eating window and its feasibility.

The effect of time of eating on cardiometabolic risk in primary and secondary prevention of cardiovascular disease

Continuous energy restriction is currently considered the first-line dietary therapy for weight loss in individuals with obesity. Recently, interventions which alter the eating window and time of eating occasions have been explored as means to achieve weight loss and other cardiometabolic improvements such as a reduction in blood pressure, glycaemia, lipids and inflammation. It is unknown, however, whether these changes result from unintentional energy restriction or from other mechanisms such as the alignment of nutrient intake with the internal circadian clock. Even less is known regarding the safety and efficacy of these interventions in individuals with established chronic noncommunicable disease states, such as cardiovascular disease. This review examines the effects of interventions which alter both eating window and time of eating occasions on weight and other cardiometabolic risk factors in both healthy participants and those with established cardiovascular disease. We then summarise the state of existing knowledge and explore future directions of study.

The effects of different intermittent fasting regimens in people with type 2 diabetes: a network meta-analysis

Objective

To compare the effects of four intermittent fasting regimens on blood glucose and insulin sensitivity in people with type 2 diabetes.

Methods

Randomized controlled trials of intermittent fasting in the treatment of patients with type 2 diabetes mellitus in PubMed, the Cochrane Library, Embase, ScienceDirect, Web of Science, CNKI, VIP Database, and WANFANG Database were searched for from the library to September 2023. 2 review authors independently screened studies and extracted data. RevMan 5.4 was used for direct comparison of meta-results. Network meta-analysis was performed using Stata16 software.

Results

13 studies with a total of 867 patients were included. The intervention effects of twice-per-week fasting, fasting-mimicking diet, time-restricted eating, and peridic fasting were better than that of conventional diet. The results of the network comparison showed that there was no significant difference in the intervention effect of the intermittent fasting regimens. SUCRA ranking results showed that the twice-per-week fasting was best for comprehensive interventions for improvement.

Conclusion

From the perspective of fasting blood glucose, glycated hemoglobin and insulin resistance, the twice-per-week fasting intervention has a good effect, which can be used as a reference for patients with inter-type 2 diabetes to choose intermittent fasting regimen. However, more clinical trials are needed to verify this at a later stage.

Network meta-analysis of three different forms of intermittent energy restrictions for overweight or obese adults

This network meta-analysis aimed to compare the efficacy of three forms of intermittent energy restriction (IER), including alternate-day fasting (ADF), the 5:2 diet, and time-restricted feeding (TRF), in overweight or obese adults. A literature search was conducted in PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) to find relevant randomized controlled trials (RCTs) until August 10, 2022. The modified Cochrane risk of bias assessment tool was applied to assess the methodological quality of eligible studies. Random network meta-analysis was conducted using STATA 14.0. Sixteen RCTs were included, with 1228 patients. Overall, the methodological quality ranged from low to moderate. ADF was superior to CER and 5:2 diet in reducing waist circumference, whereas 5:2 diet was superior to CER in reducing BMI. Regarding fat mass and drop-out, all forms of IER were comparable. Sensitivity analyses indicated that the type of individuals had no influence on the pooled results; nevertheless, ADF significantly reduced weight compared to CER and achieved significant waist circumference reduction compared to CER, 5:2 diet, and TRF. ADF may be preferentially prescribed for overweight or obese adults. More large-scale and high-quality studies are required, however, to investigate the effect of TRF on overweight and obesity.

Intermittent Fasting and Its Effects on Weight, Glycemia, Lipids, and Blood Pressure: A Narrative Review

Metabolic syndrome (MetS) has become a significant public health concern globally. Weight managementis crucial in controlling MetS risk factors, making energy balance and weight loss strategies important in nutrition recommendations. Intermittent fasting (IF) has gained traction as a dietary approach for weight management and cardiovascular risk reduction. However, the effects of IF on cardiovascular risk factors have been inconsistent in previous studies. This review aims to summarize the effects of various types of IF on body mass index (BMI), glycemia, lipid profile, and blood pressure, while providing insights into their clinical implications. A comprehensive search of interventional studies and meta-analyses was conducted, and the results were analyzed. The findings indicate that different types of IF lead to mixed effects. Time-restricted eating (TRE) and alternate-day fasting (ADF) consistently showed decreases in BMI, while the outcomes of intermittent energy restriction (IER) were more uncertain. The effects of IF on glycemia and lipid profile were also variable, with TRE and ADF generally showing positive results. However, the impact of IER remained inconsistent. More research is needed to understand the long-term effects and optimal implementation of IF for managing metabolic syndrome and cardiovascular risk factors.

Intermittent Fasting Sustainably Improves Glucose Tolerance in Normal Weight Male Mice Through Histone Hyperacetylation

To explore the mechanism by which intermittent fasting (IF) exerts prolonged effects after discontinuation, we examined mice that had been subjected to 4 cycles of fasting for 72 hours and ad libitum feeding for 96 hours per week (72hIF), followed by 4 weeks of ad libitum feeding, focusing on expression of genes for lipid metabolism in the skeletal muscle and histone acetylation in the promoter region. The 72hIF regimen resulted in metabolic remodeling, characterized by enhanced lipid utilization and mitochondrial activation in the muscle. This long-term IF (72hIF) caused stronger metabolic effects than alternate day fasting (24hIF) wherein fasting and refeeding are repeated every 24 hours. Upregulation of lipid oxidation genes and an increase in oxygen utilization were sustained even at 4 weeks after discontinuation of 72hIF, associated with histone hyperacetylation of the promoter region of uncoupling protein 3 (Ucp3) and carnitine palmitoyl transferase 1b (Cpt1b) genes. An increase in leucine owing to fasting-induced muscle degradation was suggested to lead to the histone acetylation. These findings support the previously unappreciated notion that sustainable promotion of histone acetylation in lipid oxidation genes of the muscle and adipose tissues during and after IF may contribute to sustained metabolic effects of IF.

Effects of Intermittent Fasting on Regulation of Metabolic Homeostasis: A Systematic Review and Meta-Analysis in Health and Metabolic-Related Disorders

Intermittent fasting (IF) is an emerging dietetic intervention that has been associated with improved metabolic parameters. Nowadays, the most common IF protocols are Alternate-Day Fasting (ADF) and Time-Restricted Fasting (TRF), but in this review and meta-analysis we have also considered Religious Fasting (RF), which is similar to TRF but against the circadian rhythm. The available studies usually include the analysis of a single specific IF protocol on different metabolic outcomes. Herein, we decided to go further and to conduct a systematic review and meta-analysis on the advantages of different IF protocols for metabolic homeostasis in individuals with different metabolic status, such as with obesity, diabetes mellitus type 2 (T2D) and metabolic syndrome (MetS). Systematic searches (PubMed, Scopus, Trip Database, Web of Knowledge and Embase, published before June 2022) of original articles in peer-review scientific journals focusing on IF and body composition outcomes were performed. Sixty-four reports met the eligibility criteria for the qualitative analysis and forty-seven for the quantitative analysis. Herein, we showed that ADF protocols promoted the major beneficial effects in the improvement of dysregulated metabolic conditions in comparison with TRF and RF protocols. Furthermore, obese and MetS individuals are the most benefited with the introduction of these interventions, through the improvement of adiposity, lipid homeostasis and blood pressure. For T2D individuals, IF impact was more limited, but associated with their major metabolic dysfunctions-insulin homeostasis. Importantly, through the integrated analysis of distinct metabolic-related diseases, we showed that IF seems to differently impact metabolic homeostasis depending on an individual's basal health status and type of metabolic disease.

The Effects of Isocaloric Intermittent Fasting vs Daily Caloric Restriction on Weight Loss and Metabolic Risk Factors for Noncommunicable Chronic Diseases: A Systematic Review of Randomized Controlled or Comparative Trials

BACKGROUND

Intermittent fasting (IF) has gained favor as an alternative regimen to daily caloric restriction (DCR). Therefore, there is a need for systematic reviews of randomized controlled/comparison trials examining the effects of isocaloric IF vs DCR on metabolic risk factors for noncommunicable chronic diseases.

OBJECTIVE

To systematically investigate the effects of isocaloric IF vs DCR on metabolic risk factors for noncommunicable chronic diseases in adults with overweight and obesity.

METHODS

Five online databases (PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar) were searched for articles published from January 2000 through April 2022. The updated Cochrane Risk of Bias Assessment tool for randomized controlled/comparison trials was used to assess risk of bias in the included studies. This review includes randomized controlled/comparison trials with matched energy intakes (isocaloric) between IF and DCR among adults with overweight and obesity with ≥8-week durations, that assessed risk factors related to obesity and for diabetes, cardiovascular diseases, and cancers.

RESULTS

Thirteen randomized controlled/comparison trials with matched energy intakes (isocaloric) between IF and DCR were identified. The effects of IF on weight loss and metabolic risk markers of diabetes, cardiovascular diseases, and cancers were varied but generally comparable with DCR. IF (4:3 and 5:2 diets) was superior to DCR for improving insulin sensitivity in two studies. Reductions in body fat were significantly greater with IF (5:2 diet and time-restricted eating) than DCR in two studies of isocaloric diets.

CONCLUSIONS

With matched energy intakes, IF interventions produced similar beneficial effects for weight loss and chronic disease risk factors compared with DCR. Very limited evidence suggests that IF may be more effective vs DCR for fat loss and insulin sensitivity, but conclusions cannot be drawn based on the current evidence. Future clinical studies with larger populations and longer durations are needed for further elucidation of any potential effects of IF regimens for prevention of noncommunicable chronic diseases.

[Nutrition for diabetic patients (Update 2023)]

All patients with diabetes require individual and personalized nutritional consultation with professionals. The patient's needs should be the primary focus of the dietary therapy, taking their lifestyle and the type of diabetes into consideration. With the recommendations to the patient's diet, there need to be specific metabolic goals to reduce the disease's progression and to avoid long term health effects. Therefore, practical guidelines such as portion size and meal planning tips should be the main focus.According to the latest national and international standards, patients suffering from diabetes should have access to nutrition consulting and nutritional training. During consultation they can be supported on- how to manage their health condition and choosing food and beverage to improve their health.These practical recommendations sum up the latest literature on nutritional aspects of diabetes treatment.

Compliance of participants undergoing a '5-2' intermittent fasting diet and impact on body weight

BACKGROUND

Intermittent fasting (IF) has grown in popularity as a weight loss tool, where caloric intake is fully/partially restricted on a recurring basis. This study aimed to assess compliance with IF fast-day calorie restriction and whether 5-2 IF leads to reduced overall energy intake, weight loss and compensatory increased energy intake on non-fast days.

METHOD

Participants completed diet diaries at baseline and 28 days post 5-2 IF in a repeated measures within-subjects design. 5-2 IF required restricted energy intake to 500 kcal/day (women), 650 kcal/day (men) on two 'fast' days/week whilst eating ad-libitum on other days.

RESULTS

52 participants were included (n = 42 female; age 44 ± 11.2yrs). Median weight loss after 28 days 5-2 IF was statistically significant (1.8 [-2 - 7.3 IQR = 2.2]kg; 2.8 [-2.7-11.2 IQR = 2.5]% p < 0.001). There was a significant reduction in total energy intake during 5-2 IF compared with pre-diet (median 1288.0 [IQR 423.8]kcal and median 1751.5 [IQR 505.3]kcal respectively, p < 0.001). Carbohydrate, protein and fat consumption proportionately reduced during 5-2 IF. Participants had significantly higher energy intake (p < 0.001) on non-fast days that followed a fast day (1928.4 ± 711.9 kcal) compared to non-fast days not following a fast day (1316.2 ± 310.0 kcal). 55.8% complied with fast day calorie restrictions.

CONCLUSION

5-2 IF was associated with significantly reduced energy intake, and weight loss over a 28-day period. Compliance rate was lower than most previous studies. Participants had significantly higher energy intake on non-fast days following fast days suggesting fasting may lead to over-compensation. Further research should investigate strategies to improve compliance and long-term sustainability of IF diets.

Management of hyperglycaemia in type 2 diabetes, 2022. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the previous consensus statements on the management of hyperglycaemia in type 2 diabetes in adults, published since 2006 and last updated in 2019. The target audience is the full spectrum of the professional healthcare team providing diabetes care in the USA and Europe. A systematic examination of publications since 2018 informed new recommendations. These include additional focus on social determinants of health, the healthcare system and physical activity behaviours including sleep. There is a greater emphasis on weight management as part of the holistic approach to diabetes management. The results of cardiovascular and kidney outcomes trials involving sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists, including assessment of subgroups, inform broader recommendations for cardiorenal protection in people with diabetes at high risk of cardiorenal disease. After a summary listing of consensus recommendations, practical tips for implementation are provided.

Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the previous consensus statements on the management of hyperglycemia in type 2 diabetes in adults, published since 2006 and last updated in 2019. The target audience is the full spectrum of the professional health care team providing diabetes care in the U.S. and Europe. A systematic examination of publications since 2018 informed new recommendations. These include additional focus on social determinants of health, the health care system, and physical activity behaviors, including sleep. There is a greater emphasis on weight management as part of the holistic approach to diabetes management. The results of cardiovascular and kidney outcomes trials involving sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists, including assessment of subgroups, inform broader recommendations for cardiorenal protection in people with diabetes at high risk of cardiorenal disease. After a summary listing of consensus recommendations, practical tips for implementation are provided.

Updated Meta-Analysis of Studies from 2011 to 2021 Comparing the Effectiveness of Intermittent Energy Restriction and Continuous Energy Restriction

Background

Despite the considerable number of trials and meta-analyses of studies on intermittent energy restriction (IER), it is not preferred to continuous energy restriction (CER) by the majority of obesity specialists. In this meta-analysis, we compare the effects of IER and CER on obesity using evidence from randomized controlled trials (RCTs).

Methods

A systematic electronic literature search was conducted to find RCTs published between January 1, 2011, and December 31, 2021 that directly compared IER and CER for an active weight loss period of at least 12 weeks and reported obesity indices or metabolic markers in adults with overweight or obesity. Finally, 16 RCTs from 25 articles with 1,438 participants were included.

Results

The attrition rates were 26.6% and 24.1% in the IER and CER groups, respectively, with no significant differences in changes in body weight, waist circumference, or body fat composition. CER changed blood glucose levels more than IER, but there was no significant difference in glycated hemoglobin levels. Systolic blood pressure was significantly lower in the CER group than the IER group, but diastolic blood pressure did not differ significantly between the groups. Changes in blood lipids did not differ significantly between the interventions. No differences between IER and CER were observed in the sensitivity analyses.

Conclusion

IER can be an alternative to CER because it induces comparable weight reduction and metabolic improvement. However, the effect of IER was not superior to that of CER, and its attrition rate was not lower than that of CER.

Comparison of weight loss induced by daily caloric restriction versus intermittent fasting (DRIFT) in individuals with obesity: study protocol for a 52-week randomized clinical trial

BACKGROUND

The standard of care for treating overweight and obesity is daily caloric restriction (DCR). While this approach produces modest weight loss, adherence to DCR declines over time and weight regain is common. Intermittent fasting (IMF) is an alternative dietary strategy for reducing energy intake (EI) that involves >60% energy restriction on 2-3 days per week, or on alternate days, with habitual intake on fed days. While numerous studies have evaluated IMF as a weight loss strategy, there are several limitations including lack of a standard-of-care DCR control, failure to provide guideline-based behavioral support, and failure to rigorously evaluate dietary and PA adherence using objective measures. To date, only three longer-term (52-week) trials have evaluated IMF as a weight loss strategy. None of these longer-duration studies reported significant differences between IMF and DCR in changes in weight. However, each of these studies has limitations that prohibit drawing generalizable conclusions about the relative long-term efficacy of IMF vs. DCR for obesity treatment.

METHODS

The Daily Caloric Restriction vs. Intermittent Fasting Trial (DRIFT) is a two-arm, 52-week block randomized (1:1) clinical weight loss trial. The two intervention arms (DCR and IMF) are designed to prescribe an equivalent average weekly energy deficit from baseline weight maintenance energy requirements. Both DCR and IMF will be provided guideline-based behavioral support and a PA prescription. The primary outcome is change in body weight at 52 weeks. Secondary outcomes include changes in body composition (dual-energy x-ray absorptiometry (DXA)), metabolic parameters, total daily energy expenditure (TDEE, doubly labeled water (DLW)), EI (DLW intake-balance method, 7-day diet diaries), and patterns of physical activity (PA, activPAL device).

DISCUSSION

Although DCR leads to modest weight loss success in the short-term, there is wide inter-individual variability in weight loss and poor long-term weight loss maintenance. Evidence-based dietary approaches to energy restriction that are effective long-term are needed to provide a range of evidence-based options to individuals seeking weight loss. The DRIFT study will evaluate the long-term effectiveness of IMF vs. DCR on changes in objectively measured weight, EI, and PA, when these approaches are delivered using guideline-based behavioral support and PA prescriptions.

Comparison of the Effects of Intermittent Energy Restriction and Continuous Energy Restriction among Adults with Overweight or Obesity: An Overview of Systematic Reviews and Meta-Analyses

There is considerable heterogeneity across the evidence regarding the effects of intermittent energy restriction and continuous energy restriction among adults with overweight or obesity which presents difficulties for healthcare decision-makers and individuals. This overview of systematic reviews aimed to evaluate and synthesize the existing evidence regarding the comparison of the two interventions. We conducted a search strategy in eight databases from the databases’ inception to December 2021. The quality of 12 systematic reviews was assessed with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) and the Grading of Recommendations Assessment, Development and Evaluation (GRADE). One review was rated as high quality, 1 as moderate, 4 as low, and 6 as critically low. A meta-analysis of the original studies was conducted for comparison of primary intermittent energy restriction protocols with continuous energy restriction. Intermittent energy restriction did not seem to be more effective in weight loss compared with continuous energy restriction. The advantages of intermittent energy restriction in reducing BMI and waist circumference and improvement of body composition were not determined due to insufficient evidence. The evidence quality of systematic reviews and original trials remains to be improved in future studies.

Understanding weight regain after a nutritional weight loss intervention: Systematic review and meta-analysis

BACKGROUND & AIMS

The purpose of this systematic review was to analyze the effects of lifestyle interventions on long-term weight maintenance of weight loss. In addition, we seek to address which period is most susceptible to weight regain; and what is the time required for following-up weight maintenance after the intervention.

METHODS

Articles published up to August 2020 were identified using the Medline (PubMed), Embase, Web of Science, CENTRAL and Scopus.

RESULTS

After the selection process, 27 clinical trials involving 7236 individuals were included. The results showed that around 36 weeks after the end of the intervention, weight variation reduces, and a sign of continuous weight gain begin to occur with some patients (n = 208,209) presenting even a completely regain of the lost weight before one year (∼40-48 weeks). However, some strategies used during the weight loss intervention and maintenance period may impact the amount and when the weight regain happens, like intervention type;, intervention duration;, presence of dietitian on the care team;, and maintenance period with counseling by a health professional at least once a month.

CONCLUSION

This systematic review and meta-analysis showed that lifestyle interventions remained effective in maintaining the mean weight (5% lower than baseline weight) after weight loss interventions were over. However, weight regain started 36 weeks after intervention conclusion. And, it turns out, some strategies used during the weight loss intervention and maintenance period may impact the amount and when the weight regain happens. Obesity complexity and chronicity should be considered, therefore constant and lifelong monitoring and support are important.

Intermittent Energy Restriction for Weight Loss: A Systematic Review of Cardiometabolic, Inflammatory and Appetite Outcomes

Current guidelines for obesity treatment recommend reducing daily caloric intake for weight loss. However, long-term weight loss continues to be an issue in obesity management. Alternative weight loss strategies have increased in popularity, such as intermittent energy restriction (IER), a type of eating pattern with periods of fasting alternating with unrestricted eating. The effects of IER on weight loss, cardiovascular risk factors, inflammation, and appetite are not clear. The purpose of this systematic review was to analyze short- (<24 weeks) and long-term (≥24 weeks) effects of IER on anthropometric, cardiometabolic, inflammatory, and appetite outcomes in adults with overweight/obesity. PubMed, CINAHL, Embase, and PsycInfo were searched from inception to July 2020. Human randomized controlled trials (RCTs) on IER with participants with a body mass index ≥25 kg/m² were included in this review. A total of 42 articles (reporting on 27 different RCTs) were included. In short-term studies, IER showed pre-to-post treatment improvements in eight of nine studies that assessed weight. Weight outcomes were sustained in the long-term. However, no significant long-term between group differences were observed in fat mass, other anthropometric, cardiometabolic, inflammatory, or appetite outcomes. Compared to continuous energy restriction (CER), IER showed no significant long-term differences in anthropometric, cardiometabolic, inflammatory, or appetite outcomes in included studies. More long-term studies are needed to assess the benefits of IER on health outcomes.

Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss?

We conducted a systematic review and meta-analysis of randomized clinical trials and pilot trial studies to compare the effectiveness of intermittent fasting (IF) and continuous calorie restriction (CCR) in overweight and obese people. The parameters included body mass index (BMI), body weight, and other metabolism-related indicators. A systematic search in PubMed, Embase, Cochrane Library, and Web of Science was conducted up to January 2022. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to measure the effectiveness. Publication bias was assessed using Egger’s test. The stability of the results was evaluated using sensitivity analyses. The significance of body weight change (SMD = −0.21, 95% CI (−0.40, −0.02) p = 0.028) was more significant after IF than CCR. There was no significant difference in BMI (SMD = 0.02, 95% CI (−0.16, 0.20) p = 0.848) between IF and CCR. These findings suggest that IF may be superior to CCR for weight loss in some respects.

Beneficial effects of intermittent fasting: a narrative review

Caloric restriction is a popular approach to treat obesity and its associated chronic illnesses but is difficult to maintain for a long time. Intermittent fasting is an alternative and easily applicable dietary intervention for caloric restriction. Moreover, intermittent fasting has beneficial effects equivalent to those of caloric restriction in terms of body weight control, improvements in glucose homeostasis and lipid profiles, and anti-inflammatory effects. In this review, the beneficial effects of intermittent fasting are discussed.

Intermittent Fasting: Potential Bridge of Obesity and Diabetes to Health?

Obesity has been an escalating worldwide health problem for decades, and it is likely a risk factor of prediabetes and diabetes. Correlated with obesity, the number of diabetic patients is also remarkable. A modest weight loss (5–10%) is critical to alleviate the risk of any other metabolic disease. Reduced energy intake has been an essential factor for weight loss reduction. As a new behavior intervention to lose weight, intermittent fasting (IF) attracts considerable attention and has become a popular strategy among young people. IF is a diet pattern that cycles between periods of fasting and eating on a regular schedule, involving various types, mainly Intermittent Energy Restriction and Time-Restricted Fasting. Accumulating evidence shows that short-term IF has a greatly positive effect in animal studies and contributes favorable benefits in human trials as well. Nevertheless, as an emerging, diverse, and relatively premature behavior intervention, there are still limited studies considering patients with obesity and type 2 diabetes mellitus. It is also a controversial intervention for the treatment of metabolic disease and cancer. The risks and challenges appear consequently. Additionally, whether intermittent fasting can be applied to long-term clinical treatment, and whether it has side effects during the long-term period or not, demands more large-scale and long-term experiments.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7-10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

Effect of Intermittent Fasting Diet on Glucose and Lipid Metabolism and Insulin Resistance in Patients with Impaired Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis

The question of whether or not intermittent fasting diets improve the clinical indicators of glycolipid metabolism remains unclear. This study systematically reviewed the relevant clinical trials to evaluate the effects of intermittent fasting diet on glucose and lipid metabolism and insulin sensitivity in patients with metabolic syndrome. To evaluate the effect of intermittent fasting diet intervention on patients with disorders of glucose and lipid metabolism, random-effect or fixed-effect meta-analysis models were used to calculate the average difference before and after intermittent fasting diet intervention and the corresponding 95% confidence intervals (CIs). After intermittent fasting diet intervention, in terms of glucose metabolism, fasting blood glucose reduced by 0.15 mmol/L (95% CI: -0.23; -0.06), glycosylated hemoglobin reduced by 0.08 (95% CIs: -0.25; -0.10), insulin plasma levels reduced by 13.25 uUI (95% CIs: -16.69; -9.82), and HOMA-IR decreased by 0.31 on an average (95% CIs: -0.44; -0.19). In addition, BMI decreased by 0.8 kg/m² (95% CIs: -1.32; -0.28), body weight reduced by 1.87 kg (95% CIs: -2.67; -1.07), and the waist circumference decreased by 2.08 cm (95% CIs: -3.06; -1.10). Analysis of lipid metabolism showed that intermittent fasting diet intervention effectively reduced the total cholesterol level by 0.32 mmol/L (95% CIs: -0.60; -0.05), low-density lipoprotein level by 0.22 mmol/L (95% CIs: -0.37; -0.07), and triglyceride level by 0.04 mmol/L (95% CIs: -0.15; -0.07). Intermittent fasting diets have certain therapeutic effects on blood glucose and lipids in patients with metabolic syndrome and significantly improve insulin resistance. It may be considered as an auxiliary treatment to prevent the occurrence and development of chronic diseases.

Time-restricted feeding improves blood glucose and insulin sensitivity in overweight patients with type 2 diabetes: a randomised controlled trial

Background

Time-restricted feeding is an emerging dietary intervention that is becoming increasingly popular. There are, however, no randomised clinical trials of time-restricted feeding in overweight patients with type 2 diabetes. Here, we explored the effects of time-restricted feeding on glycaemic regulation and weight changes in overweight patients with type 2 diabetes over 12 weeks.

Methods

Overweight adults with type 2 diabetes (n = 120) were randomised 1:1 to two diet groups: time-restricted feeding (n = 60) or control (n = 60). Sixty patients participated in a 10-h restricted feeding treatment program (ad libitum feeding from 8:00 to 18:00 h; fasting between 18:00 and 8:00 h) for 12 weeks.

Results

Haemoglobin A1c and body weight decreased in the time-restricted feeding group (− 1.54% ± 0.19 and − 2.98 ± 0.43 kg, respectively) relative to the control group over 12 weeks (p < 0.001). Homeostatic model assessment of β-cell function and insulin resistance changed in the time-restricted feeding group (0.73 ± 0.21, p = 0.005; − 0.51 ± 0.08, p = 0.02, respectively) compared with the control group. The medication effect score, SF-12 score, and the levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol were improved in the time-restricted feeding group (− 0.66 ± 0.17, p = 0.006; 5.92 ± 1.38, p < 0.001; − 0.23 ± 0.08 mmol/L, p = 0.03; − 0.32 ± 0.07 mmol/L, p = 0.01; − 0.42 ± 0.13 mmol/L, p = 0.02, respectively) relative to the control group. High-density lipoprotein cholesterol was not significantly different between the two groups.

Conclusion

These results suggest that 10-h restricted feeding improves blood glucose and insulin sensitivity, results in weight loss, reduces the necessary dosage of hypoglycaemic drugs and enhances quality of life. It can also offer cardiovascular benefits by reducing atherosclerotic lipid levels.

Trial registration: This study was registered with the Chinese Clinical Trial Registry (ChiCTR-IPR-15006371).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00613-9.

Intermittent fasting versus continuous energy-restricted diet for patients with type 2 diabetes mellitus and metabolic syndrome for glycemic control: A systematic review and meta-analysis of randomized controlled trials

AIMS

To compare the safety of intermittent fasting (IF) with that of continuous energy-restricted diets (CERD) in patients with T2DM and metabolic syndrome who were overweight or obese and assess their effects on glycemic control and weight loss.

MATERIALS AND METHODS

We searched MEDLINE (Ovid), Embase, and SINOMED databases up to September 13, 2020. The major outcome was glycemic control and secondary outcomes were change in weight, fasting insulin, and lipid profile.

RESULTS

Of 84 retrieved studies, 5 met our inclusion criteria. Of these, four studies comprising 355 participants were included in the meta-analysis. Based on changes in HbA1c (-0.06, 95% confidence interval [CI] -0.27 to 0.16) and fasting plasma glucose (-0.27, 95% CI -0.76 to 0.22), IF and CERD had similar effects on glycemic control. Moreover, IF had a better effect on weight loss (-1.70, 95% CI -3.28 to -0.11 kg). Patients in both groups experienced similar improvements in fasting insulin and lipid profile as well as similar hypoglycemic events.

CONCLUSIONS

IF is a safe diet pattern and could be implemented for patients with T2DM or metabolic syndrome. Further studies with a larger sample size are needed to verify the effectiveness and safety of IF in patients with T2DM.

Time-Restricted Eating, Intermittent Fasting, and Fasting-Mimicking Diets in Weight Loss

PURPOSE OF REVIEW

This article reviews the current literature on dietary interventions, including time-restricted eating (TRE), intermittent fasting (IF), and fasting-mimicking diets (FMD) and their effects on weight loss.

RECENT FINDINGS

Dietary interventions, primarily known for their potential health benefits, are attracting considerable interest also for their effects on weight loss. The literature suggests that many popular diets can induce weight loss but only a limited number of studies actually demonstrate long-term weight loss efficacy. Here we present an update on the latest studies on some of the most popular dietary interventions able to trigger the physiology of fasting and highlight their impact on weight loss in overweight or obese individuals.

Adherence and Dietary Composition during Intermittent vs. Continuous Calorie Restriction: Follow-Up Data from a Randomized Controlled Trial in Adults with Overweight or Obesity

Although intermittent calorie restriction (ICR) has become popular as an alternative weight loss strategy to continuous calorie restriction (CCR), there is insufficient evidence on diet quality during ICR and on its feasibility over longer time periods. Thus, we compared dietary composition and adherence between ICR and CCR in a follow-up analysis of a randomized trial. A total of 98 participants with overweight or obesity [BMI (kg/m²) 25-39.9, 35-65 years, 49% females] were randomly assigned to ICR, operationalized as a "5:2 diet" (energy intake: ~100% on five non-restricted (NR) days, ~25% on two restricted (R) days), or CCR (daily energy intake: ~80%). The trial included a 12-week (wk) intervention phase, and follow-up assessments at wk24, wk50 and wk102. Apart from a higher proportion of energy intake from protein with ICR vs. CCR during the intervention (wk2: p < 0.001; wk12: p = 0.002), there were no significant differences with respect to changes in dietary composition over time between the groups, while overall adherence to the interventions appeared to be good. No significant difference between ICR and CCR regarding weight change at wk102 was observed (p = 0.63). However, self-reported adherence was worse for ICR than CCR, with 71.1% vs. 32.5% of the participants reporting not to or only rarely have followed the regimen to which they were assigned between wk50 and wk102. These results indicate that within a weight management setting, ICR and CCR were equivalent in achieving modest weight loss over two years while affecting dietary composition in a comparable manner.

Intermittent and continuous energy restriction result in similar weight loss, weight loss maintenance, and body composition changes in a 6 month randomized pilot study

Poor adherence is a barrier to successful weight control. Intermittent energy restriction (IER) provides an alternative approach to those for whom daily energy restriction is not ideal. This study assessed changes in weight, body composition, and macronutrient intake for an IER and a continuous energy restriction (CONT) approach within a multicomponent weight management intervention. We randomized 35 adults with overweight/obesity (BMI = 31.2 ± 2.4 kg/m² ) to CONT or IER for 24 weeks (12-week weight loss intervention and 12 weeks of weight loss maintenance). Diets were delivered within a multimodal weight management program including weekly group meetings with a registered dietitian, increased physical activity, and a comprehensive lifestyle change program. Retention and adherence were similar for CONT and IER. Weight, BMI, fat mass, percentage body fat, waist circumference, hip circumference, blood pressure, and heart rate all decreased after 24 weeks (all, P < .01), but there were no main effects of group (all, P > .27). Weight loss was clinically relevant in both CONT (11.38 ± 7.9%) and IER (9.37 ± 9.7%), and the proportion of each group achieving 5% weight loss was 82 and 61% (P = .16), respectively. Participant satisfaction was high in both groups. The results from this study (a) support the feasibility of IER as an alternative for weight loss and weight loss maintenance, (b) indicate that IER is an effective alternative to CONT for weight control and improvements in body composition, and (c) emphasize the importance of intensive lifestyle interventions with ongoing support for effective behaviour modification.

Intermittent Versus Continuous Energy Restriction for Weight Loss and Metabolic Improvement: A Meta-Analysis and Systematic Review

OBJECTIVE

This study aimed to evaluate the effects of intermittent energy restriction (IER; only for 2-3 d/wk) versus continuous energy restriction (CER) on weight loss and metabolic outcomes in adults with overweight or obesity.

METHODS

Methods included searching databases from the last decade to December 18, 2019, for randomized controlled trials (RCTs) that assessed weight loss and metabolic outcomes in IER and CER. RevMan version 5.3 software was used for statistical analysis of the data. The effect sizes were expressed as weight mean differences and 95% CI.

RESULTS

This review included 11 RCTs (n = 850). Meta-analysis showed that IER had greater effects on absolute weight loss, the percentage of weight loss, and improving insulin sensitivity than CER. In the subgroup analysis, short-term (2-3 months) intervention (P < 0.0001) was associated with weight loss.

CONCLUSIONS

This systematic review shows that IER (2-3 d/wk) had greater effects on short-term weight loss than CER and that IER results in comparative metabolic improvements. Furthermore, longer RCTs are needed to validate these findings.

Effectiveness of an intermittent fasting diet versus continuous energy restriction on anthropometric measurements, body composition and lipid profile in overweight and obese adults: a meta-analysis

The effects of an intermittent fasting (IF) diet in the overweight or obese adult population are still controversial. This study aimed to evaluate the effectiveness of an IF diet to reduce anthropometric parameters (body mass index, body weight, and waist circumference), change body composition (fat mass, lean body mass and muscle mass) and lipid profile (total cholesterol, HDL-c, LDL-c and triglycerides), and to adhere to the diet in comparison to continuous energy restriction (CER) in overweight or obese adults. A research question PICO (patients, intervention, comparison, outcome) was established. PubMed, Scopus, Web of Science, Cochrane, and Scielo databases were searched to identify randomized clinical trials that compared an IF diet with a CER diet or a regular diet. DeCS and MeSH descriptors and Boolean operators (AND and OR) were used. From 859 studies identified through the literature search, 18 articles were finally selected. Overall, IF diets were associated with higher weight loss in four studies and similar reduction in waist circumference in one study, compared with a CER regimen. Fat mass tended to decrease more in the IF groups in five studies. However, the lean and muscle mass loss was similar in both groups. Only three studies observed significant differences in lipid profile variables, mostly in the IF groups. Adherence to the diet was inconclusive. An IF diet may provide a benefit by improving anthropometry, body composition, and lipid profile in overweight or obese adult population, likewise a CER diet.

The Effects of Intermittent Fasting on Glycemic Control and Body Composition in Adults with Obesity and Type 2 Diabetes: A Systematic Review

The purpose of this study was to evaluate the effects of intermittent fasting on glycemic control and body composition in adults with obesity and type 2 diabetes. Although intermittent fasting has shown some promise in improving glucoregulatory indicators and body composition in adults with obesity, there is currently no systematic review evaluating these effects in adults with obesity and type 2 diabetes. A database search of PubMed, CINHAL, and MEDLINE identified five studies that met inclusion criterion. All studies were randomized controlled trials in adult subjects (n = 46-137) with type 2 diabetes and a body mass index of ≥30 kg/m². Four different intermittent fasting regimens were reviewed. All fasting regimens revealed strong evidence to support intermittent fasting as a feasible diet to improve glycemia and body composition measures within 12-24 weeks. Follow-up 12-18 months after intermittent fasting did not show promising results for continued weight loss and improved glycemic control. The majority of the studies demonstrated insignificant differences between intermittent fasting and continuous energy restriction for measures of glycated hemoglobin a1c and body composition. More data on intermittent fasting in adults with obesity and type 2 diabetes are needed to determine its benefits within this patient population. Future research should include consistent fasting regimens and larger sample sizes to improve the reliability and generalizability of the data. Also, consistent follow-up after a fasting intervention may enhance long-term benefits and should be considered in future research.

Intermittent Fasting and Metabolic Health: From Religious Fast to Time-Restricted Feeding

Over the past 10 to 15 years, intermittent fasting has emerged as an unconventional approach to reduce body weight and improve metabolic health beyond simple calorie restriction. In this review, we summarize findings related to Ramadan and Sunnah fasting. We then discuss the role of caloric restriction not only as an intervention for weight control, but importantly, as a strategy for healthy aging and longevity. Finally, we review the four most common intermittent fasting (IF) strategies used to date for weight management and to improve cardiometabolic health. Weight loss is common after IF but does not appear to be different than daily caloric restriction when compared directly. IF may also provide additional cardiometabolic benefit, such as insulin sensitization, that is independent from weight loss. While no specific fasting regimen stands out as superior at this time, there is indeed heterogeneity in responses to these different IF diets. This suggests that one dietary regimen may not be ideally suited for every individual. Future studies should consider strategies for tailoring dietary prescriptions, including IF, based on advanced phenotyping and genotyping prior to diet initiation.

Efficacy of Intermittent or Continuous Very Low-Energy Diets in Overweight and Obese Individuals with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analyses

OBJECTIVE

This study is aimed at investigating the efficacy of a very low-energy diet (VLED) in overweight and obese individuals with type 2 diabetes mellitus (T2DM).

METHODS

We thoroughly searched eight electronic resource databases of controlled studies concerning the efficacy and acceptability of intermittent or continuous VLEDs in patients with T2DM compared with other energy restriction interventions.

RESULTS

Eighteen studies (11 randomized and seven nonrandomized controlled trials) with 911 participants were included. The meta-analyses showed that compared with a low-energy diet (LED) and mild energy restriction (MER), VLED is superior in the reduction of body weight (mean difference (MD) MD_LED = -2.77, 95% confidence interval (CI) CI_LED = -4.81 to - 0.72, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, I ² = 0%) and TG level (MD = -0.25, 95%CI = -0.55 to 0.06, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, I ² = 0%) and TG level (MD = -0.25, 95%CI = -0.55 to 0.06, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39, P _LED = 0.008; MD_MER = -6.72, 95%CI_MER = -10.05 to - 3.39.

CONCLUSION

Dietary intervention through VLEDs is an effective therapy for rapid weight loss, glycemic control, and improved lipid metabolism in overweight and obese individuals with T2DM. Thus, VLEDs should be encouraged in overweight and obese individuals with T2DM who urgently need weight loss and are unsuitable or unwilling to undergo surgery. As all outcome indicators have low or extremely low quality after GRADE evaluation, further clinical trials that focus on the remission effect of VLEDs on T2DM are needed.