Evaluation of meal replacements and a home food environment intervention for long-term weight loss: a randomized controlled trial

Meal replacements on obesity and leptin: a systematic review and meta-analysis

The global prevalence of obesity and overweight is a significant concern in the field of public health. Numerous interventional studies have been conducted to assess the possible meal replacements (MRs) effect on anthropometric indicators and indices and laboratory test that reflect obesity. However, there are no comprehensive results in this field. The study aim was to understand the possible effects of MRs on body weight, body mass index (BMI), fat mass, waist circumferences (WC), and leptin levels. A systematic search was conducted in five electronic databases in order to find randomized clinical trials (RCTs) that examined the possible MRs effect on obesity. Analyses were performed in R software, version 4.2.1. The random-effects model analysis was used to provide pooled mean difference and 95% confidence intervals (95% CI). Seventy studies were included. Body weight (WMD: -3.35 kg, 95% CI: -4.28 to -2.42), BMI (WMD: -1.12 kg/m2, 95% CI: -1.51 to -0.72), fat mass (WMD: -2.77 kg, 95% CI: -3.59 to -1.6), WC (WMD: -2.82 cm, 95% CI: -3.51 to -2.12) were significantly reduced after MRs compared to control. No significant effect was observed on leptin (WMD: -3.37 ng/ml, 95% CI: -8.23 to 1.49). Subgroup analyses indicated that impact of total MRs on anthropometric factors was greater in comparison to partial MRs. Considering other lifestyle factors, MRs can lead to anthropometric indicators and indices reduction.

Weight regain after total meal replacement very low-calorie diet program with and with-out anti-obesity medications

Background

Very low-calorie diets (VLCDs) employing total meal replacement (TMR) offer substantial short-term weight loss. Concurrently, anti-obesity medications (AOMs) have shown promise as adjunctive treatments when combined with VLCDs.

Aims

This study aimed to investigate the impact of adjuvant AOMs on weight loss and weight regain within a comprehensive lifestyle program.

Methods

This is a retrospective study of patients with obesity enrolled in VLCD/TMR programs,  specifically the OPTIFAST program.

Results

Data from 206 patients (68% women, mean age 52.39 ± 13.05 years, BMI 41.71 ± 7.04 kg/m2) were analyzed. Of these, 139 received no AOM (AOM-), while 67 received AOMs (AOM+). Total body weight loss percentages (TWL%) at 6 and 18 months were -17.87% ± 7.02 and -12.10% ± 11.56, respectively. There was no significant difference in 6-month weight loss between the AOM groups. However, the AOM + group exhibited lower weight regain (3.29 kg ± 10.19 vs. 7.61 kg ± 11.96; p = 0.006) and weight regain percentage (WR%) (31.5% ± 68.7 vs. 52.16% ± 64.4; p = 0.04) compared with the AOM- group.

Conclusion

The findings highlighted the potential of AOMs and VLCD/TMR as effective strategies for long-term weight management in individuals with obesity.

New insights in the mechanisms of weight-loss maintenance: Summary from a Pennington symposium

Obesity is a chronic disease that affects more than 650 million adults worldwide. Obesity not only is a significant health concern on its own, but predisposes to cardiometabolic comorbidities, including coronary heart disease, dyslipidemia, hypertension, type 2 diabetes, and some cancers. Lifestyle interventions effectively promote weight loss of 5% to 10%, and pharmacological and surgical interventions even more, with some novel approved drugs inducing up to an average of 25% weight loss. Yet, maintaining weight loss over the long-term remains extremely challenging, and subsequent weight gain is typical. The mechanisms underlying weight regain remain to be fully elucidated. The purpose of this Pennington Biomedical Scientific Symposium was to review and highlight the complex interplay between the physiological, behavioral, and environmental systems controlling energy intake and expenditure. Each of these contributions were further discussed in the context of weight-loss maintenance, and systems-level viewpoints were highlighted to interpret gaps in current approaches. The invited speakers built upon the science of obesity and weight loss to collectively propose future research directions that will aid in revealing the complicated mechanisms involved in the weight-reduced state.

Study protocol for a randomized, controlled trial using a novel, family-centered diet treatment to prevent nonalcoholic fatty liver disease in Hispanic children

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the leading liver disorder among U.S. children and is most prevalent among Hispanic children with obesity. Previous research has shown that reducing the consumption of free sugars (added sugars + naturally occurring sugars in fruit juice) can reverse liver steatosis in adolescents with NAFLD. This study aims to determine if a low-free sugar diet (LFSD) can prevent liver fat accumulation and NAFLD in high-risk children.

METHODS

In this randomized controlled trial, we will enroll 140 Hispanic children aged 6 to 9 years who are ≥50th percentile BMI and without a previous diagnosis of NAFLD. Participants will be randomly assigned to either an experimental (LFSD) or a control (usual diet + educational materials) group. The one-year intervention includes removal of foods high in free sugars from the home at baseline, provision of LFSD household groceries for the entire family (weeks 1-4, 12, 24, and 36), dietitian-guided family grocery shopping sessions (weeks 12, 24, and 36), and ongoing education and motivational interviewing to promote LFSD. Both groups complete assessment measures at baseline, 6, 12, 18, and 24 months. Primary study outcomes are percent hepatic fat at 12 months and incidence of clinically significant hepatic steatosis (>5%) + elevated liver enzymes at 24 months. Secondary outcomes include metabolic markers potentially mediating or moderating NAFLD pathogenesis.

DISCUSSION

This protocol describes the rationale, eligibility criteria, recruitment strategies, analysis plan as well as a novel dietary intervention design. Study results will inform future dietary guidelines for pediatric NAFLD prevention.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05292352.

Overlapping and distinct relationships between hedonic hunger, uncontrolled eating, food craving, and the obesogenic home food environment during and after a 12-month behavioral weight loss program

Hedonic hunger, reward-driven eating outside of biological need, is a newer construct in eating behavior research. During behavioral weight loss (BWL), greater improvements in hedonic hunger are associated with higher weight loss, but it remains unclear if hedonic hunger predicts weight loss independent of more well-established, similar constructs (uncontrolled eating and food craving). Research also is needed to understand how hedonic hunger interacts with contextual factors (e.g., obesogenic food environment) during weight loss. Adults (N = 283) in a 12-month randomized controlled trial of BWL were weighed at 0, 12, and 24 months, and completed questionnaires assessing hedonic hunger, food craving, uncontrolled eating, and the home food environment. All variables improved at 12 and 24 months. Decreases in hedonic hunger at 12 months were associated with higher concurrent weight loss, but not when accounting for improvements in craving and uncontrolled eating. At 24 months, reduction in craving was a stronger predictor of weight loss than hedonic hunger, but improvement in hedonic hunger was a stronger predictor of weight loss than change in uncontrolled eating. Changes to the obesogenic home food environment failed to predict weight loss, regardless of levels of hedonic hunger. This study adds novel information on the individual and contextual factors associated with short- and long-term weight control, which can help refine conceptual models and treatment strategies.

Spatiotemporal profile of altered neural reactivity to food images in obesity: Reward system is altered automatically and predicts efficacy of weight loss intervention

Introduction

Obesity presents a significant public health problem. Brain plays a central role in etiology and maintenance of obesity. Prior neuroimaging studies have found that individuals with obesity exhibit altered neural responses to images of food within the brain reward system and related brain networks. However, little is known about the dynamics of these neural responses or their relationship to later weight change. In particular, it is unknown if in obesity, the altered reward response to food images emerges early and automatically, or later, in the controlled stage of processing. It also remains unclear if the pretreatment reward system reactivity to food images is predictive of subsequent weight loss intervention outcome.

Methods

In this study, we presented high-calorie and low-calorie food, and nonfood images to individuals with obesity, who were then prescribed lifestyle changes, and matched normal-weight controls, and examined neural reactivity using magnetoencephalography (MEG). We performed whole-brain analysis to explore and characterize large-scale dynamics of brain systems affected in obesity, and tested two specific hypotheses: (1) in obese individuals, the altered reward system reactivity to food images occurs early and automatically, and (2) pretreatment reward system reactivity predicts the outcome of lifestyle weight loss intervention, with reduced activity associated with successful weight loss.

Results

We identified a distributed set of brain regions and their precise temporal dynamics that showed altered response patterns in obesity. Specifically, we found reduced neural reactivity to food images in brain networks of reward and cognitive control, and elevated reactivity in regions of attentional control and visual processing. The hypoactivity in reward system emerged early, in the automatic stage of processing (< 150 ms post-stimulus). Reduced reward and attention responsivity, and elevated neural cognitive control were predictive of weight loss after six months in treatment.

Discussion

In summary, we have identified, for the first time with high temporal resolution, the large-scale dynamics of brain reactivity to food images in obese versus normal-weight individuals, and have confirmed both our hypotheses. These findings have important implications for our understanding of neurocognition and eating behavior in obesity, and can facilitate development of novel integrated treatment strategies, including tailored cognitive-behavioral and pharmacological therapies.

The ironic effects of dietary restraint in situations that undermine self-regulation

Dietary restraint, defined as the cognitive effort to restrict eating, can paradoxically make individuals more susceptible to unhealthy eating when their ability to self-regulate is threatened. Past experiments have found that, in situations that elicit low self-control and/or unhealthy cravings, participants with higher dietary restraint eat more than those with lower restraint. However, these relationships have never been examined in a free-living environment. The current daily diary study examined if dietary restraint would exacerbate the associations between poor self-control and unhealthy cravings with overconsumption, namely, eating more than usual and binge eating. College women (N = 121, M age = 19) reported their restrained eating behavior and completed seven daily surveys. Multilevel analyses showed a significant interaction between dietary restraint and daily self-control on eating more than usual (b = -0.13, p = .001) and binge eating (b = -0.22, p < .001). Lower daily self-control was associated with eating more than usual and with more binge eating that day, but only among women with higher dietary restraint. Dietary restraint also moderated the effect of cravings on eating more than usual (b = 0.10, p = .007); this relationship was stronger for women with higher restraint. Stronger cravings were associated with more binge eating regardless of restraint. Results suggest that situations that undermine self-control are more strongly associated with overeating among those with higher dietary restraint. Findings can inform strategies to reduce overconsumption among restrained eaters.

Meal replacement by formula diet reduces weight more than a lifestyle intervention alone in patients with overweight or obesity and accompanied cardiovascular risk factors-the ACOORH trial

BACKGROUND

As formula diets have demonstrated to be effective in reducing weight, we hypothesised that in patients with overweight or obesity and accompanied cardiovascular risk factors, combining a liquid formula diet with a lifestyle intervention is superior in reducing weight and improving cardiovascular risk factors than lifestyle intervention alone.

METHODS

In this multicenter RCT 463 participants with overweight or obesity (BMI: 27-35 kg/m²; at least one additional co-morbidity of the metabolic syndrome) were randomised (1:2) into either a control group with lifestyle intervention only (CON, n = 155) or a lifestyle intervention group including a liquid meal replacement (INT, n = 308). Both groups used telemonitoring devices (scales and pedometers), received information on healthy diet and were instructed to increase physical activity. Telemonitoring devices automatically transferred data into a personalised online portal and acquired data were discussed. INT obtained a liquid meal replacement substituting three meals/day (~1200 kcal) within the first week. During weeks 2-4, participants replaced two meals/day and during weeks 5-26 only one meal/day was substituted (1300-1500 kcal/day). Follow-up was conducted after 52 weeks. Intention-to-treat analyses were performed. Primary outcome was weight change. Secondary outcomes comprised changes in cardiometabolic risk factors including body composition and laboratory parameters.

RESULTS

From the starting cohort 360 (78%, INT: n = 244; CON: n = 116) and 317 (68%, INT: n = 216; CON: n = 101) participants completed the 26-weeks intervention phase and the 52-weeks follow-up. The estimated treatment difference (ETD) between both groups was -3.2 kg [-4.0; -2.5] (P < 0.001) after 12 weeks and -1.8 kg [-2.8; -0.8] (P < 0.001) after 52 weeks.

CONCLUSIONS

A low-intensity lifestyle intervention combined with a liquid meal replacement is superior regarding weight reduction and improvement of cardiovascular risk factors than lifestyle intervention alone.

Long-term sustainability of a physical activity and nutrition intervention for rural adults with or at risk of metabolic syndrome

OBJECTIVE

To determine longer-term (18-month) sustainability of a six-month physical activity and nutrition intervention for 50-69-year-olds with or at risk of metabolic syndrome residing in a rural Australian community.

METHODS

Participants (n=151) were followed-up at 12 and 18 months post-intervention. Changes in nutrition behaviours (fat and fibre barometer); physical activity behaviours (IPAQ); anthropometry (waist-hip ratio, weight, BMI), blood pressure, blood parameters (triglycerides, glucose, LDL-, HDL-, non-HDL, total-cholesterol) were analysed using t-tests and repeated measures ANOVA.

RESULTS

Across three time points (6, 12 and 18 months) marginal decrease was observed for waist circumference (p=0.001), a modest increase was observed for diastolic blood pressure (p=0.010) and other outcome measures remained stable.

CONCLUSION

Maintenance and ongoing improvement of health behaviours in the longer-term is challenging. Future studies must look for ways to embed interventions into communities so they are sustainable and investigate new approaches to reduce the risk of chronic disease. Implications for public health: Metabolic syndrome is a major health issue in Australia and worldwide. Early identification and management are required to prevent the progression to chronic disease. This 18-month follow-up showed that outcomes measures remained relatively stable; however, there is a need to investigate opportunities for embedded community interventions to support long-term health behaviour change.

Weight Change 2 Years After Termination of the Intensive Lifestyle Intervention in the Look AHEAD Study

OBJECTIVE

This study evaluated weight changes after cessation of the 10-year intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study. It was hypothesized that ILI participants would be more likely to gain weight during the 2-year observational period following termination of weight-loss-maintenance counseling than would participants in the diabetes support and education (DSE) control group.

METHODS

Look AHEAD was a randomized controlled trial that compared the effects of ILI and DSE on cardiovascular morbidity and mortality in participants with overweight/obesity and type 2 diabetes. Look AHEAD was converted to an observational study in September 2012.

RESULTS

Two years after the end of the intervention (EOI), ILI and DSE participants lost a mean  (SE) of 1.2  (0.2) kg and 1.8  (0.2) kg, respectively (P = 0.003). In addition, 31% of ILI and 23.9% of DSE participants gained ≥ 2% (P < 0.001) of EOI weight, whereas 36.3% and 45.9% of the respective groups lost ≥ 2% of EOI weight (P = 0.001). Two years after the EOI, ILI participants reported greater use of weight-control behaviors than DSE participants.

CONCLUSIONS

Both groups lost weight during the 2-year follow-up period, but more ILI than DSE participants gained ≥ 2% of EOI weight. Further understanding is needed of factors that affected long-term weight change in both groups.

Weight variability during self-monitored weight loss predicts future weight loss outcome

BACKGROUND

Obesity treatments often do not produce long-term results. It is therefore critical to better understand biological and behavioral correlates or predictors of future weight change.

OBJECTIVE

We tested the hypothesis that greater weight variability, independent of total body weight change, during early weight loss would predict degree of long-term success.

SUBJECTS/METHODS

We included 24,009 American users of the Withings smart scale with over a year's worth of self-monitored weight data. Multilevel modeling was used to calculate weight variability as the root mean square error around participants' weight trajectory regression line, using weekly average weights from the first 12 weeks of weight loss. Linear regressions were then used to examine whether weight variability predicted weight change from week 12 to week 48, 72, and 96.

RESULTS

Greater weight variability predicted less weight loss/more weight regain at week 48 (b ± SE: 1.18 ± 0.17, p < 0.001), week 72 (b ± SE: 1.45 ± 0.21, p < 0.001), and week 96 (b ± SE: 1.45 ± 0.23, p < 0.001), controlling for baseline BMI and overall weight change during the first 12 weeks. An interaction effect was found between weight variability and baseline BMI such that the relationship between weight variability and later weight change was stronger in individuals with lower baseline BMI.

CONCLUSIONS

This study found that in a large population sample, weight variability early on during weight loss significantly predicted longer term weight loss outcomes. The results provide further support that weight variability be considered an important predictor of future weight change. Research is needed to understand the mechanisms underlying this effect.

A systematic review and meta-analysis of the effectiveness of meal replacements for weight loss

Meal replacements (MR) are generally not recommended in clinical guidelines for the management of obesity. The aim of this review is to provide an up-to-date systematic evaluation of the effect of weight loss interventions incorporating MR compared with alternative interventions on weight change at 1 year in adults with overweight or obesity. Six electronic databases were searched from inception to the end of August 2018 for randomized controlled trials comparing the effect of MR with interventions that did not include MR on weight at 1 year. We excluded studies using diets providing <3347 kJ/(800 kcal)/day and those which used total diet replacement (TDR) from this review. Risk of bias was assessed using the Cochrane risk of bias tool. Twenty-three studies with 7884 adult participants were included. Six out of 23 studies were judged at low risk of bias across all domains, and 5/23 studies were judged at high risk of bias in at least one domain. Studies with similar intervention and comparators were grouped into five comparisons for analysis. Mean weight change at 1 year favoured the MR group relative to the control group in each comparison. In those comparisons where we conducted meta-analysis, in people assigned to a diet incorporating MR, mean difference was -1.44 kg (-2.48 to -0.39 kg; I²  = 38%) compared with alternative kinds of diets. In those assigned to a MR diet along with support, mean difference was -2.22 kg (-3.99 to -0.45, I²  = 81%) compared with other diets with support and -3.87 kg (-7.34 to -0.40; I²  = 60%) compared with other kinds of diet without support. In those assigned a MR diet with an enhanced level of support, mean difference was -6.13 kg (-7.35 to -4.91, I²  = 19%) compared with alternative diets and regular support. Programmes incorporating meal replacements led to greater weight loss at 1 year than comparator weight loss programmes and should be considered as a valid option for management of overweight and obesity in community and health care settings.

White Sweet Potato as Meal Replacement for Overweight White-Collar Workers: A Randomized Controlled Trial

Overweight and obesity are a global concern. Meal replacements (MRs) are portion- and calorie-controlled meals, which make the food environment part of an individual’s weight loss regimen. White sweet potato (WSP; Ipomoea batatas L.), used in traditional medicine in Brazil, Japan, and Taiwan, is a healthy carbohydrate source. In this randomized controlled trial, we assessed the effects of a WSP formula on body weight management in 58 white-collar workers through MR to elucidate the effects of this WSP-MR on factors leading to overweight. The participants consumed either two packs a day for a total of 132 g of WSP (WSP-MR group) or a normal diet daily (non-WSP group) for eight weeks. After eight weeks, body weight, body fat, body mass index, wrist circumference, thigh circumference, calf circumference, mid-arm circumference, and triceps skinfolds decreased significantly in both the groups. Moreover, the WSP-MR group demonstrated a 5% decrease in body weight, body fat, body mass index, and mid-arm circumference and a 3.5% decrease in glycated hemoglobin levels (p < 0.05). The treatment was well tolerated, without side effects or adverse events. Thus, our WSP formula as an MR can facilitate individual weight loss and thus has commercial application in the food industry.