Clinical correlates of weight loss and attrition during a 10-week dietary intervention study: results from the NUGENOB project

Impact of baseline adipose tissue characteristics on change in adipose tissue volume during a low calorie diet in people with obesity-results from the LION study

BACKGROUND/OBJECTIVES

Weight loss outcomes vary individually. Magnetic resonance imaging (MRI)-based evaluation of adipose tissue (AT) might help to identify AT characteristics that predict AT loss. This study aimed to assess the impact of an 8-week low-calorie diet (LCD) on different AT depots and to identify predictors of short-term AT loss using MRI in adults with obesity.

METHODS

Eighty-one adults with obesity (mean BMI 34.08 ± 2.75 kg/m², mean age 46.3 ± 10.97 years, 49 females) prospectively underwent baseline MRI (liver dome to femoral head) and anthropometric measurements (BMI, waist-to-hip-ratio, body fat), followed by a post-LCD-examination. Visceral and subcutaneous AT (VAT and SAT) volumes and AT fat fraction were extracted from the MRI data. Apparent lipid volumes based on MRI were calculated as approximation for the lipid contained in the AT. SAT and VAT volumes were subdivided into equidistant thirds along the craniocaudal axis and normalized by length of the segmentation. T-tests compared baseline and follow-up measurements and sex differences. Effect sizes on subdivided AT volumes were compared. Spearman Rank correlation explored associations between baseline parameters and AT loss. Multiple regression analysis identified baseline predictors for AT loss.

RESULTS

Following the LCD, participants exhibited significant weight loss (11.61 ± 3.07 kg, p < 0.01) and reductions in all MRI-based AT parameters (p < 0.01). Absolute SAT loss exceeded VAT loss, while relative apparent lipid loss was higher in VAT (both p < 0.01). The lower abdominopelvic third showed the most significant SAT and VAT reduction. The predictor of most AT and apparent lipid losses was the normalized baseline SAT volume in the lower abdominopelvic third, with smaller volumes favoring greater AT loss (p < 0.01 for SAT and VAT loss and SAT apparent lipid volume loss).

CONCLUSIONS

The LCD primarily reduces lower abdominopelvic SAT and VAT. Furthermore, lower abdominopelvic SAT volume was detected as a potential predictor for short-term AT loss in persons with obesity.

A predictive model for medium-term weight loss response in people with type 2 diabetes engaging in behavioural weight management interventions

AIMS

To develop and evaluate prediction models for medium-term weight loss response in behavioural weight management programmes.

MATERIALS AND METHODS

We conducted three longitudinal analyses using the Action for HEalth in Diabetes (LookAHEAD) trial, Weight loss Referrals for Adults in Primary care (WRAP) trial, and routine data from the National Health Service Greater Glasgow and Clyde Weight Management Service (NHS-GGCWMS). We investigated predictors of medium-term weight loss (>5% body weight) over 3 years in NHS-GGCWMS and, separately, predictors of weight loss response in LookAHEAD over 4 years. We validated predictors in both studies using WRAP over 5 years. Predictors of interest included demographic and clinical variables, early weight change in-programme (first 4 weeks) and overall in-programme weight change.

RESULTS

In LookAHEAD and WRAP the only baseline variables consistently associated with weight loss response were female sex and older age. Of 1152 participants in NHS-GGCWMS (mean age 57.8 years, 60% female, type 2 diabetes diagnosed for a median of 5.3 years), 139 lost weight over 3 years (12%). The strongest predictor of weight loss response was early weight change (odds ratio 2.22, 95% confidence interval 1.92-2.56) per 1% weight loss. Losing 0.5% weight in the first 4 weeks predicted medium-term weight loss (sensitivity 89.9%, specificity 49.5%, negative predictive value 97.3%). Overall in-programme weight change was also associated with weight loss response over 3 years in NHS-GGCWMS and over 5 years in WRAP.

CONCLUSIONS

Not attaining a weight loss threshold of 0.5% early in weight management programmes may identify participants who would benefit from alternative interventions.

Importance of early weight loss and other predictors of lower weight loss in a commercial program: A secondary data analysis

Objective

There is substantial inter-individual variability in response to weight loss interventions and emerging evidence suggests that weight loss during the early weeks of an intervention may be predictive of longer-term weight loss. This secondary analysis of data from a commercial program therefore examined 1) the associations between early weight loss (i.e., week 4) with final visit weight loss and duration on the program, and 2) other predictors of lower weight loss at final visit.

Methods

Client charts of adults with overweight or obesity (N = 748) were analyzed. Clients were stratified into categories of weight loss at the week 4 (< and ≥2%, 3% and 4%) and final visits (< and ≥5% and 10%). Multivariate logistic regression was used to assess predictors of <5% and <10% final visit weight loss.

Results

The odds ratios for losing <5% or <10% of weight at the final visit were higher (49.0 (95% CI: 13.84, 173.63) and 20.1 (95% CI: 6.96, 58.06)) for clients who lost <2% or <3% compared to those who lost ≥2% or ≥3% at week 4. Other predictors of not losing a clinically relevant amount of weight included female sex, use of higher calorie meal plans and shorter time in the program, among others. Those who lost ≥2% at week 4 also had a significantly greater percent program completion (109.2 ± 75.2% vs. 82.3 ± 82.4, p < 0.01) compared with those who did not meet the 2% threshold.

Conclusions

Lower 4-week weight loss was identified as a strong predictor of not losing a clinically relevant amount of weight. These results may be useful for the early identification of individuals who can be targeted for additional counseling and support to aid in attaining weight loss goals.

Initial weight loss and early intervention adherence predict long-term weight loss during the Promoting Successful Weight Loss in Primary Care in Louisiana lifestyle intervention

OBJECTIVE

This study tested whether initial weight change (WC), self-weighing, and adherence to the expected WC trajectory predict longer-term WC in an underserved primary-care population with obesity.

METHODS

Data from the intervention group (n = 452; 88% women; 74% Black; BMI 37.3 kg/m2 [SD: 4.6]) of the Promoting Successful Weight Loss in Primary Care in Louisiana trial were analyzed. Initial (2-, 4-, and 8-week) percentage WC was calculated from baseline clinic weights and daily at-home weights. Weights were considered adherent if they were on the expected WC trajectory (10% at 6 months with lower [7.5%] and upper [12.5%] bounds). Linear mixed-effects models tested whether initial WC and the number of daily and adherent weights predicted WC at 6, 12, and 24 months.

RESULTS

Percentage WC during the initial 2, 4, and 8 weeks predicted percentage WC at 6 (R2  = 0.15, R2  = 0.28, and R2  = 0.50), 12 (R2  = 0.11, R2  = 0.19, and R2  = 0.32), and 24 (R2  = 0.09, R2  = 0.11, and R2  = 0.16) months (all p < 0.01). Initial daily and adherent weights were significantly associated with WC as individual predictors, but they only marginally improved predictions beyond initial weight loss alone in multivariable models.

CONCLUSIONS

These results highlight the importance of initial WC for predicting long-term WC and show that self-weighing and adherence to the expected WC trajectory can improve WC prediction.

Initial Weight Loss, Anthropometric Parameters, and Proinflammatory Transcript Levels in Patients with Class I Obesity

Research into early predictors of effective weight loss could help determine more effective therapeutic interventions. In this study, 106 subjects with class I obesity, genotyped with the fat mass and obesity-associated (FTO) rs9930506 gene variant, were enrolled into a 12-week weight loss program (WLP). Anthropometric and body composition measurements were controlled with bioelectrical impedance analysis (BIA) at baseline and after 4 and 12 weeks. Biopsies of abdominal subcutaneous adipose tissue (AT) and venous blood samples were collected to monitor changes in interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κB) mRNA levels in white blood cells (WBCs) and to assess if changes in WBC gene expression reflected changes in adipose tissue. The FTO rs9930506 variant had no effect on weight loss and no reduction in proinflammatory transcripts in WBCs or AT. Changes in anthropometric parameters were associated with changes in carbohydrate metabolism. A linear regression model showed that initial weight loss (after 4 weeks of the WLP) was the most predictive factor of weight loss success after 12 weeks of the WLP. Changes in plasma lipids or proinflammatory transcript levels in WBCs or AT were not associated with weight loss effectiveness. However, the gene expression in WBCs did reflect changes occurring in subcutaneous AT.

Duration of Treatment in a Weight Loss Program Using a Mobile App is Associated with Successful Weight Loss During the COVID-19 Pandemic

PURPOSE

We aimed to explore the independent factors associated with successful weight loss using a mobile app during the COVID-19 pandemic.

PATIENTS AND METHODS

For this retrospective cohort study, we collected data from 45 adults in a weight loss program using a mobile app. We defined successful weight loss as a weight reduction by ≥ 5% of the baseline weight. Multivariate logistic analysis was used to assess potential factors influencing successful weight loss.

RESULTS

All subjects showed a mean 4.1 ± 4.4 kg reduction of baseline weight after using the app for a mean duration of 11 weeks (P < 0.001). Subjects in the successful weight loss group displayed a longer duration of treatment (14.6 ± 6.5 weeks vs 6.9 ± 6.0 weeks, P < 0.001), greater number of dietary records (109.2 ± 84.7 vs 54.7 ± 58.8, P = 0.002), and greater number of outpatient visits (6.1 ± 2.7 vs 3.7 ± 2.3, P < 0.001) than those in the unsuccessful weight loss group. Multivariate logistic analysis showed that duration of treatment was an independent factor associated with successful weight loss (odds ratio = 1.23, 95% confidence interval: 1.08-1.41, P = 0.003).

CONCLUSION

In a weight management program using a mobile app during the COVID-19 pandemic, the duration of treatment was found to be an independent factor of successful weight loss.

Obese patients' characteristics and weight loss outcomes in cardiac rehabilitation: An observational study of registry data

AIM

Cardiac rehabilitation (CR) guidelines advocate weight loss for obese patients but mean weight loss is small. We sought to determine the extent to which obese patients' characteristics prior to CR predict weight loss.

METHODS

An observational, pre- and post CR study of routine practice using the UK National Audit of Cardiac Rehabilitation dataset was undertaken. Backward, stepwise, multiple linear regression analysis was used to identify characteristics prior to CR that predicted weight change in obese patients.

RESULTS

In 29,601 obese patients undertaking CR, mean weight loss was 0.9 kg (SD 4.3; p < 0.001) in men (74% of sample) and 0.5 kg (SD 3.9; p < 0.001) in women. Smoking cessation since the cardiac event independently predicted less weight loss by 1.2 kg (95% CI; 0.9, 1.5 kg; p < 0.001). Diabetes, cardiac surgery, living in a deprived area, being female, low fitness levels and pain independently predicted less weight loss during CR. Higher initial weight, greater age and being employed predicted increased weight loss.

CONCLUSION

This is the first study to identify how the characteristics of obese patients independently predict different amounts of weight loss during CR in free-living individuals. It is also the largest, registry-based study to investigate predictors of weight loss in obese patients in CR. Knowledge of the extent to which obese patients' characteristics predict more or less weight loss can aid: the generation of guidelines; agreement of realistic goals with patients; and tailoring of weight management support.

Predictors of successful weight loss outcomes amongst individuals with obesity undergoing lifestyle interventions: A systematic review

Understanding the predictors of weight loss with lifestyle interventions can help to ascertain the probable outcomes of individuals with obesity who undergo such interventions. This systematic review assessed the evidence of predictors of successful weight loss among individuals who are overweight or with obesity undergoing lifestyle interventions. Four electronic databases (PubMed, Cochrane Reviews, PsychInfo and Wiley) were searched to find relevant literature published in the past 20 years. A total of 1351 titles were identified in the initial search, of which 23 studies were finally included. Predictors were synthesized in the domains of socio-demographic factors, anthropometric parameters, psychological and behavioural factors and intervention-based factors. The overall quality of evidence on predictors was then appraised using an adapted GRADE approach. Patient-specific factors such as being male, older in age, having existing cardiometabolic comorbidities and limited fat intake were significantly associated with weight loss success. Amongst intervention specific predictors, greater initial weight loss and higher adherence to lifestyle advice were associated with greater weight loss success. In this review, initial weight loss came out to be as the most important predictor of successful weight loss outcome.

Intermediate weight changes and follow-up of dietetic treatment in primary health care: an observational study

BACKGROUND

Primary health care data have shown that most patients who were treated for overweight or obesity by a dietitian did not accomplish the recommended treatment period. It is hypothesised that a slow rate of weight loss might discourage patients from continuing dietetic treatment. This study evaluated intermediate weight changes during regular dietetic treatment in Dutch primary health care, and examined whether weight losses at previous consultations were associated with attendance at follow-up consultations.

METHODS

This observational study was based on real life practice data of overweight and obese patients during the period 2013-2017, derived from Dutch dietetic practices that participated in the Nivel Primary Care Database. Multilevel regression analyses were conducted to estimate the mean changes in body mass index (BMI) during six consecutive consultations and to calculate odds ratios for the association of weight change at previous consultations with attendance at follow-up consultations.

RESULTS

The total study population consisted of 25,588 overweight or obese patients, with a mean initial BMI of 32.7 kg/m². The BMI decreased between consecutive consultations, with the highest weight losses between the first and second consultation. After six consultations, a mean weight loss of - 1.5 kg/m² was estimated. Patients who lost weight between the two previous consultations were more likely to attend the next consultation than patients who did not lose weight or gained weight.

CONCLUSIONS

Body mass index decreased during consecutive consultations, and intermediate weight losses were associated with a higher attendance at follow-up consultations during dietetic treatment in overweight patients. Dietitians should therefore focus on discussing intermediate weight loss expectations with their patients.

Is Dietary Nonadherence Unique to Obesity and Weight Loss? Results From a Randomized Clinical Trial

OBJECTIVE

Weight stigma is associated with poor dietary adherence, yet adherence is essential for weight loss and maintenance. This study aimed to determine differences in dietary adherence and perceived hunger between lean individuals and two groups of individuals with obesity.

METHODS

In a 6-week outpatient dietary intervention (23 males; aged 48  [SD 14] years), lean participants (n = 23; BMI 23  [SD 2] kg/m² ) received a weight-maintaining energy needs (WMEN) diet, and participants with obesity (BMI 36  [SD 7]) were randomized to either WMEN (n = 18) or a 35% calorie-reduced (CR) diet (n = 19). All food was provided, and multiple adherence and hunger ratings were assessed daily and weekly on an outpatient basis and in person at twice-weekly visits (e.g., 24-hour recall, diaries).

RESULTS

Weight decreased more in the group of CR individuals with obesity (β = -0.301 kg/wk, P = 0.02) compared with the group of lean individuals and the group of WMEN individuals with obesity. However, total percent adherence did not differ between groups (P = 0.60), and hunger scores did not change across groups over time (P = 0.08).

CONCLUSIONS

Results indicate that there are no differences in dietary adherence between lean individuals and individuals with obesity and adherence is not associated with adiposity or hunger. Thus, the belief that nonadherence (e.g., lack of willpower) is unique to obesity is untrue and may perpetuate weight bias and stigma.

The role of dietary protein in obesity

Protein-rich diets are surging in popularity for weight loss. An increase in diet-induced thermogenesis, better preservation of fat-free mass, and enhanced satiety with greater dietary protein intakes may lead to increased energy expenditure and decreased energy intake; and thus promote a more negative energy balance that facilitates weight loss. Results from large randomized trials and meta-analyses of many smaller trials indicate that high-protein diets typically induce significantly greater amounts of weight loss than conventional low-fat or high-carbohydrate diets during the early, rapid weight loss phase (3-6 months), but differences between diets are attenuated and no longer significant during the late, slow weight loss phase (12-24 months). Gradually decreasing adherence may be responsible for this observation; in fact, dietary adherence, rather than macronutrient composition, is likely the major predictor of long-term weight loss success. Recently, some randomized trials evaluated the efficacy of high-protein (vs. normal-protein) diets consumed ad libitum during weight loss maintenance, i.e. after clinically significant weight loss. Weight regain may be smaller with high-protein diets in the short-term (3-12 months), but longer studies are needed to confirm this. Given the lack of conclusive evidence in favor of high-protein diets, or any other dietary pattern, it is reasonable to conclude that no individual nutrient is a friend or a foe when it comes to weight loss and its maintenance. Therefore, any diet that best suits one's dietary habits and food preferences is likely to be better adhered to, and thus lead to more successful long-term weight loss.

Greater Attendance at a Community Weight Loss Programme over the First 12 Weeks Predicts Weight Loss at 2 Years

BACKGROUND

There is considerable heterogeneity in long-term weight loss among people referred to obesity treatment programmes. It is unclear whether attendance at face-to-face sessions in the early weeks of the programme is an independent predictor of long-term success.

OBJECTIVE

To investigate whether frequency of attendance at a community weight loss programme over the first 12 weeks is associated with long-term weight change.

METHODS

Participants were randomised to receive brief support only (control, n = 211), or a weight loss programme for 12 weeks (n = 530) or 52 weeks (n = 528). This study included participants with data on session attendance over the first 12 weeks (n = 889) compared to the control group. The association between attendance (continuously) and weight loss was explored using a linear model. A multi-level mixed-effects linear model was used to investigate whether attendance (categorised as 0, 1, 2-5, 6-9, and 10-12 sessions) was associated with weight loss at 3, 12, and 24 months compared to the control.

RESULTS

For every session attended in the first 12 weeks, the average weight loss was -0.259 kg/session at 24 months (p = 0.005). Analysis by attendance group found only those attending 10-12 sessions had significantly greater weight loss (-7.5 kg [95% CI -8.1 to -6.9] at 12 months; -4.7 kg [95% CI -5.3 to -4.1] at 24 months) compared to the control group (-3.4 [95% CI -4.5 to -2.4] at 12 months, -2.5 [95% CI -3.5 to -1.5] at 24 months). Early attendance was higher for people ≥70 years, but there was no evidence of a difference by gender, ethnicity, education, or income.

CONCLUSIONS

Greater attendance at a community weight loss programme in the first 12 weeks is associated with enhanced weight loss up to 24 months. Regular attendance at a programme could be used as a criterion for continued provision of weight loss services to maximise the cost-effectiveness of interventions.

Contribution of macronutrients to obesity: implications for precision nutrition

The specific metabolic contribution of consuming different energy-yielding macronutrients (namely, carbohydrates, protein and lipids) to obesity is a matter of active debate. In this Review, we summarize the current research concerning associations between the intake of different macronutrients and weight gain and adiposity. We discuss insights into possible differential mechanistic pathways where macronutrients might act on either appetite or adipogenesis to cause weight gain. We also explore the role of dietary macronutrient distribution on thermogenesis or energy expenditure for weight loss and maintenance. On the basis of the data discussed, we describe a novel way to manage excessive body weight; namely, prescribing personalized diets with different macronutrient compositions according to the individual's genotype and/or enterotype. In this context, the interplay of macronutrient consumption with obesity incidence involves mechanisms that affect appetite, thermogenesis and metabolism, and the outcomes of these mechanisms are altered by an individual's genotype and microbiota. Indeed, the interactions of the genetic make-up and/or microbiota features of a person with specific macronutrient intakes or dietary pattern consumption help to explain individualized responses to macronutrients and food patterns, which might represent key factors for comprehensive precision nutrition recommendations and personalized obesity management.

Modeling of an integrative prototype based on genetic, phenotypic, and environmental information for personalized prescription of energy-restricted diets in overweight/obese subjects

BACKGROUND

Interindividual variability in weight loss and metabolic responses depends upon interactions between genetic, phenotypic, and environmental factors.

OBJECTIVE

We aimed to model an integrative (nutri) prototype based on genetic, phenotypic, and environmental information for the personalized prescription of energy-restricted diets with different macronutrient distribution.

METHODS

A 4-mo nutritional intervention was conducted in 305 overweight/obese volunteers involving 2 energy-restricted diets (30% restriction) with different macronutrient distribution: a moderately high-protein (MHP) diet (30% proteins, 30% lipids, and 40% carbohydrates) and a low-fat (LF) diet (22% lipids, 18% proteins, and 60% carbohydrates). A total of 201 subjects with good dietary adherence were genotyped for 95 single nucleotide polymorphisms (SNPs) related to energy homeostasis. Genotyping was performed by targeted next-generation sequencing. Two weighted genetic risk scores for the MHP (wGRS1) and LF (wGRS2) diets were computed using statistically relevant SNPs. Multiple linear regression models were performed to estimate percentage BMI decrease depending on the dietary macronutrient composition.

RESULTS

After energy restriction, both the MHP and LF diets induced similar significant decreases in adiposity, body composition, and blood pressure, and improved the lipid profile. Furthermore, statistically relevant differences in anthropometric and biochemical markers depending on sex and age were found. BMI decrease in the MHP diet was best predicted at ∼28% (optimism-corrected adjusted R2 = 0.279) by wGRS1 and age, whereas wGRS2 and baseline energy intake explained ∼29% (optimism-corrected adjusted R2 = 0.287) of BMI decrease variability in the LF diet. The incorporation of these predictive models into a decision algorithm allowed the personalized prescription of the MHP and LF diets.

CONCLUSIONS

Different genetic, phenotypic, and exogenous factors predict BMI decreases depending on the administration of a hypocaloric MHP diet or an LF diet. This holistic approach may help to personalize dietary advice for the management of excessive body weight using precision nutrition variables.This trial was registered at clinicaltrials.gov as NCT02737267.

Models Integrating Genetic and Lifestyle Interactions on Two Adiposity Phenotypes for Personalized Prescription of Energy-Restricted Diets With Different Macronutrient Distribution

Aim: To analyze the influence of genetics and interactions with environmental factors on adiposity outcomes [waist circumference reduction (WCR) and total body fat loss (TFATL)] in response to energy-restricted diets in subjects with excessive body weight.

Materials and Methods: Two hypocaloric diets (30% energy restriction) were prescribed to overweight/obese subjects during 16 weeks, which had different targeted macronutrient distribution: a low-fat (LF) diet (22% energy from lipids) and a moderately high-protein (MHP) diet (30% energy from proteins). At the end of the trial, a total of 201 participants (LF diet = 105; MHP diet = 96) who presented good/regular dietary adherence were genotyped for 95 single nucleotide polymorphisms (SNPs) previously associated with weight loss through next-generation sequencing from oral samples. Four unweighted (uGRS) and four weighted (wGRS) genetic risk scores were computed using statistically relevant SNPs for each outcome by diet. Predictions of WCR and TFATL by diet were modeled through recognized multiple linear regression models including genetic (single SNPs, uGRS, and wGRS), phenotypic (age, sex, and WC, or TFAT at baseline), and environment variables (physical activity level and energy intake at baselines) as well as eventual interactions between genes and environmental factors.

Results: Overall, 26 different SNPs were associated with differential adiposity outcomes, 9 with WCR and 17 with TFATL, most of which were specific for each dietary intervention. In addition to conventional predictors (age, sex, lifestyle, and adiposity status at baseline), the calculated uGRS/wGRS and interactions with environmental factors were major contributors of adiposity responses. Thus, variances in TFATL-LF diet, TFATL-MHP diet, WCR-LF diet, and WCR-MHP diet were predicted by approximately 38% (optimism-corrected adj. R² = 0.3792), 32% (optimism-corrected adj. R² = 0.3208), 22% (optimism-corrected adj. R² = 0.2208), and 21% (optimism-corrected adj. R² = 0.2081), respectively.

Conclusions: Different genetic variants and interactions with environmental factors modulate the differential individual responses to MHP and LF dietary interventions. These insights and models may help to optimize personalized nutritional strategies for modeling the prevention and management of excessive adiposity through precision nutrition approaches taking into account not only genetic information but also the lifestyle/clinical factors that interplay in addition to age and sex.

Differential lipid metabolism outcomes associated with ADRB2 gene polymorphisms in response to two dietary interventions in overweight/obese subjects

BACKGROUND AND AIMS

A precise nutrigenetic management of hypercholesterolemia involves the understanding of the interactions between the individual's genotype and dietary intake. The aim of this study was to analyze the response to two dietary energy-restricted interventions on cholesterol changes in carriers of two ADRB2 polymorphisms.

METHODS AND RESULTS

A 4-month nutritional intervention was conducted involving two different hypo-energetic diets based on low-fat (LF) and moderately high-protein (MHP) dietary patterns. A total of 107 unrelated overweight/obese individuals were genotyped for two ADRB2 non-synonymous polymorphisms: Arg16Gly (rs1042713) and Gln27Glu (rs1042714). Genotyping was performed by next-generation sequencing and haplotypes were phenotypically screened. Anthropometric measurements and the biochemical profile were assessed by conventional methods. Both diets induced cholesterol decreases at the end of both nutritional interventions. Interestingly, phenotypical differences were observed according to the Arg16Gly polymorphism. Within the MHP group, Gly16Gly homozygotes had lower reductions in total cholesterol (-6.5 mg/dL vs. -24.2 mg/dL, p = 0.009), LDL-c levels (-1.4 mg/dL vs. -16.5 mg/dL, p = 0.005), and non-HDL-c (-4.5 mg/dL vs. -21.5 mg/dL, p = 0.008) than Arg16 allele carriers. Conversely, within the LF group, Gly16Gly homozygotes underwent similar falls in total cholesterol (-18.5 mg/dL vs. -18.7 mg/dL, ns), LDL-c levels (-9.7 mg/dL vs. -13.1 mg/dL, ns), and non-HDL-c (-15.3 mg/dL vs. -15.7 mg/dL, ns) than Arg16 allele carriers. The Gln27Glu polymorphism and the Gly16/Glu27 haplotype showed similar, but not greater effects.

CONCLUSIONS

An energy-restricted LF diet could be more beneficial than a MHP diet to reduce serum cholesterol, LDL-c, and non-HDL-c among Gly16Gly genotype carriers. CLINICALTRIALS.GOV: Identifier: NCT02737267.

Association of the Gly482Ser PPARGC1A gene variant with different cholesterol outcomes in response to two energy-restricted diets in subjects with excessive weight

OBJECTIVES

The aim of this study was to investigate the influence of two PPARGC1A gene polymorphisms on metabolic outcomes in response to two energy-restricted diets.

METHODS

A 4-mo nutritional intervention was conducted that involved two different hypo-energetic diets based on low-fat (LF) and moderately high-protein (MHP) dietary patterns. Unrelated subjects with excessive weight were genotyped for two PPARGC1A polymorphisms: Rs8192678 (Gly482Ser) and rs3755863 (G > A). Genotyping was performed by next-generation sequencing and haplotypes were screened. Anthropometric measurements and biochemical tests were assessed with standardized methods.

RESULTS

Different cholesterol outcomes were observed by diet and Gly482Ser genotype. The Gly482 Gly homozygotes after an LF diet had lower reductions in total cholesterol (-9 mg/dL vs. -27 mg/dL; P = 0.017) and low-density lipoprotein cholesterol levels (-5 mg/dL vs. -18 mg/dL; P = 0.016) than the subjects who were carriers of 482 Ser allele. However, this finding was not recorded in the MHP group where Gly482 Gly homozygotes underwent similar cholesterol decreases as the 482 Ser allele carriers. Likewise, all genotype carriers had significant reductions in the frequencies of hypercholesterolemia (total cholesterol ≥200 mg/dL) except for Gly482 Gly homozygotes in the LF group. Meanwhile, the rs3755863 polymorphism and PPARGC1A haplotypes showed borderline effects with regard to cholesterol decreases.

CONCLUSIONS

An energy-restricted MHP diet might be more beneficial than an LF diet to reduce serum cholesterol among subjects who are carriers of the PPARGC1A Gly482Gly genotype. The analysis of this genetic variant might be the basis for a precise, nutrigenetic management of hypercholesterolemia based on genetic makeup.

Determinants of adherence to lifestyle intervention in adults with obesity: a systematic review

Lifestyle intervention programmes are efficacious in the management of obesity but often report poor attendance and adherence rates that hinder treatment effectiveness and health outcomes. The aim of this systematic review is to identify (i) barriers to behaviour change and (ii) predictors of adherence to lifestyle intervention programmes in adults with obesity. Studies were identified by systematically reviewing the literature within Medline, PsycINFO, CINAHL, SPORTDiscus and Web of Science from inception to August 2016. Barriers to behaviour change include poor motivation; environmental, societal and social pressures; lack of time; health and physical limitations; negative thoughts/moods; socioeconomic constraints; gaps in knowledge/awareness; and lack of enjoyment of exercise. The most prominent predictors of adherence include early weight loss success, lower baseline body mass index (BMI), better baseline mood, being male and older age. The findings within this review provide novel insight to clinicians working in obesity and have important implications for lifestyle intervention programme design. Barriers to behaviour change need to be addressed early in treatment, with lifestyle intervention individualized accordingly. Predictors of adherence should also be taken into careful consideration, with negative moods and unrealistic weight loss expectations discussed at the outset. If adherence is improved, treatment effectiveness, health outcomes and the ultimate burden of chronic diseases could also be improved.

Adipose tissue morphology predicts improved insulin sensitivity following moderate or pronounced weight loss

BACKGROUND

Cross-sectional studies show that white adipose tissue hypertrophy (few, large adipocytes), in contrast to hyperplasia (many, small adipocytes), associates with insulin resistance and increased risk of developing type 2 diabetes. We investigated if baseline adipose cellularity could predict improvements in insulin sensitivity following weight loss.

METHODS

Plasma samples and subcutaneous abdominal adipose biopsies were examined in 100 overweight or obese individuals before and 10 weeks after a hypocaloric diet (7±3% weight loss) and in 61 obese subjects before and 2 years after gastric by-pass surgery (33±9% weight loss). The degree of adipose tissue hypertrophy or hyperplasia (termed the morphology value) in each individual was calculated on the basis of the relationship between fat cell volume and total fat mass. Insulin sensitivity was determined by homeostasis model assessment-estimated insulin resistance (HOMAIR).

RESULTS

In both cohorts at baseline, subjects with hypertrophy displayed significantly higher fasting plasma insulin and HOMAIR values than subjects with hyperplasia (P<0.0001), despite similar total fat mass. Plasma insulin and HOMAIR were normalized in both cohorts following weight loss. The improvement (delta insulin or delta HOMAIR) was more pronounced in individuals with hypertrophy, irrespective of whether adipose morphology was used as a continuous (P=0.0002-0.027) or nominal variable (P=0.002-0.047). Absolute adipocyte size associated (although weaker than morphology) with HOMAIR improvement only in the surgery cohort. Anthropometric measures at baseline (fat mass, body mass index, waist-to-hip ratio or waist circumference) showed no significant association with delta insulin or delta HOMAIR.

CONCLUSIONS

In contrast to anthropometric variables or fat cell size, subcutaneous adipose morphology predicts improvement in insulin sensitivity following both moderate and pronounced weight loss in overweight/obese subjects.

Weight Loss Expectations and Attrition in Treatment-Seeking Obese Women

OBJECTIVE

The analysis of the relation between weight loss goals and attrition in the treatment of obesity has produced conflicting results. The aim of the present study was to investigate the role of weight loss goals on attrition in a cohort of obese women seeking treatment at 8 Italian medical centres.

METHODS

634 women with obesity, consecutively enrolled in weight loss programmes, were included in the study. Weight loss goals were evaluated with the Goals and Relative Weights Questionnaire (GRWQ), reporting a sequence of unrealistic ('dream' and 'happy') and more realistic ('acceptable' and 'disappointing') weight loss goals. Attrition was assessed at 12 months on the basis of patients' medical records.

RESULTS

At 12 months, 205/634 patients (32.3%) had interrupted their programme and were lost to follow-up. After adjustment for age, baseline weight, education and employment status, attrition was significantly associated with higher percent acceptable and disappointing weight loss targets, not with dream and happy weight loss.

CONCLUSION

In 'real world' clinical settings, only realistic expectations might favour attrition whenever too challenging, whereas unrealistic weight loss goals have no effect. Future studies should assess the effect of interventions aimed at coping with too challenging weight goals on attrition.

Personalized weight loss strategies-the role of macronutrient distribution

A large number of different dietary approaches have been studied in an attempt to achieve healthy, sustainable weight loss among individuals with overweight and obesity. Restriction of energy intake is the primary method of producing a negative energy balance leading to weight loss. However, owing to the different metabolic roles of proteins, carbohydrates and lipids in energy homeostasis, diets of similar overall energy content but with different macronutrient distribution can differentially affect metabolism, appetite and thermogenesis. Evidence increasingly suggests that the fuel values of calories provided by distinct macronutrients should be considered separately, as metabolism of specific molecular components generates differences in energy yield. The causes of variation in individual responses to various diets are currently under debate, and some evidence suggests that differences are associated with specific genotypes. This Review discusses all available systematic reviews and meta-analyses, and summarizes the results of relevant randomized controlled intervention trials assessing the influence of macronutrient composition on weight management. The initial findings of research into personalized nutrition, based on the interactions of macronutrient intake and genetic background and its potential influence on dietary intervention strategies, are also discussed.

A weight loss program in a chiropractic practice: a retrospective analysis

CONTEXT

Obesity is a global problem and places individuals at risk for developing chronic metabolic disorders. The need for investigating simple, effective and sustaining approaches to weight loss cannot be overstated.

METHODS

We performed a retrospective file analysis of patient files attending a 13-week weight loss program. Inclusion for analysis were files of adults (i.e., >18 years) completing the program consisting of chiropractic adjustments/spinal manipulative therapy augmented with diet/nutritional intervention, exercise and one-on-one counseling.

RESULTS

Sixteen of 30 people (i.e., 53.33%) completed the program. Statistically and clinically significant changes were noted in weight and BMI measures based on pre-treatment (average weight = 190.46 lbs. and BMI = 30.94 kg/m(2)) and comparative measurements (average weight = 174.94 lbs. and BMI = 28.50 kg/m(2)).

CONCLUSION

A cohort of patients under enrolled in a weight loss program was described. This provides supporting evidence on the effectiveness of a multi-modal approach to weight loss implemented in a chiropractic clinic.