Study protocol for a 9-month randomised controlled trial assessing the effects of almonds versus carbohydrate-rich snack foods on weight loss and weight maintenance

Effects of almond consumption compared with the consumption of traditional isocaloric cereal/pulse-based snacks on glycaemic control and gut health in adults with pre-diabetes in rural India: protocol for a 16-week, parallel-arm, cluster randomised controlled trial

INTRODUCTION

Almonds have prebiotic potential to maintain gut health and regulate glycaemia. Western studies have shown their positive effects on preventing non-communicable diseases like diabetes and cardiovascular diseases. However, there is a lack of research involving Asian Indians, who have a higher predisposition to diabetes due to their unique 'Asian phenotype'. Therefore, this study aims to evaluate the impact of almond supplementation on glycaemic control and gut health in adults with pre-diabetes in rural India through a randomised clinical trial.

METHODS AND ANALYSIS

A parallel cluster randomised controlled trial with 178 participants with pre-diabetes (assigned 1:1) aged 20-50 years, of both genders, with a body mass index of 18.9-25 kg/m2, will be conducted in rural areas of Chikkaballapur, Kolar and Rural Bangalore districts in India. The intervention group will receive 56 g of almonds as mid-morning snacks for 16 weeks, while the control group will receive cereal/pulse-based traditional isocaloric snacks under the closed supervision of the study investigators. The primary outcome of the study is HbA1c measured at the 16th week. The secondary outcomes-anthropometry, clinical and other biochemical parameters-will be measured at 0th, 8th and 16th weeks, and a subgroup of 120 participants will undergo gut health analysis. Glucagon-like peptide 1 analysis will be conducted on 30 participants at 0th and 16th weeks. Statistical analysis will be performed using SPSS for Windows V.27.0, and both intention-to-treat and per-protocol analyses will be conducted.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Institutional Ethics Committee at Ramaiah Medical College, Bangalore, Karnataka, India (DRPEFP7672021). We will obtain the informed written consent of the participants prior to screening and enrolling them in the study. Results from this trial will be disseminated through publication in peer-reviewed journals and scientific gatherings.

TRIAL REGISTRATION NUMBER

Clinical Trial Registry of India (CTRI/2023/03/050421).

Effects of weight loss through dietary intervention on pain characteristics, functional mobility, and inflammation in adults with elevated adiposity

Background

The relationship between adiposity and pain is complex. Excess weight increases the risk for chronic musculoskeletal pain (CMP), driven by increased biomechanical load and low-grade systemic inflammation. Pain limits physical function, impacting energy balance contributing to weight gain. The primary aims of this study were to profile pain characteristics in participants with overweight or obesity and determine if weight loss through dietary-induced energy restriction, and presence of CMP, or magnitude of weight loss, was associated with changes in adiposity, pain, functional mobility, and inflammation.

Methods

This was a secondary analysis of data from adults (25-65 years) with overweight or obesity (BMI 27.5-34.9 kg/m2) enrolled in a 3-month, 30% energy-restricted dietary intervention to induce weight loss (January 2019-March 2021). Anthropometric measures (weight, waist circumference and fat mass), pain prevalence, pain severity (McGill Pain Questionnaire, MPQ), pain intensity (Visual Analog Scale, VAS), functional mobility (timed up and go, TUG) and inflammation (high sensitivity C-Reactive Protein, hsCRP) were assessed at baseline and 3-months.

Results

One hundred and ten participants completed the intervention and had weight and pain assessed at both baseline and 3-months. Participants lost 7.0 ± 0.3 kg, representing 7.9% ± 3.7% of body mass. At 3-months, functional mobility improved (TUG -0.2 ± 0.1 s, 95% CI -0.3, -0.1), but there was no change in hsCRP. Compared to baseline, fewer participants reported CMP at 3-months (n = 56, 51% to n = 27, 25%, p < 0.001) and presence of multisite pain decreased from 22.7% to 10.9% (p < 0.001). Improvements in anthropometric measures and functional mobility did not differ between those presenting with or without CMP at baseline. Improvements in pain were not related to the magnitude of weight loss.

Conclusion

Weight loss was effective in reducing pain prevalence and improving functional mobility, emphasizing the importance of considering weight-loss as a key component of pain management.

Clinical trial registration

identifier, ACTRN12618001861246.

Effects of energy-restricted diets with or without nuts on weight, body composition and glycaemic control in adults: a scoping review

Energy-restricted (ER) diets promote weight loss and improve body composition and glycaemic control. Nut consumption also improves these parameters. However, less is known about the combined benefit of these two strategies. This scoping review implemented a systematic search of Medline, Embase and Scopus to identify randomised controlled trials evaluating the effect of ER diets with or without nuts on body mass, body composition and glycaemic control in adults. After reviewing titles and abstracts, twenty-nine full-text articles were screened, resulting in seven studies reported in eight papers that met the inclusion criteria. Energy restriction was achieved by prescribing a set energy target or reducing intake by 1000-4200 kJ from daily energy requirements. Interventions ranged from 4 to 52 weeks in duration and contained 42-84 g/d of almonds, peanuts, pistachios or walnuts. While all studies reported that energy restriction resulted in significant weight loss, the addition of nuts to ER diets demonstrated significantly greater weight loss in only approximately half of the included studies (4/7 studies). There was limited evidence to support additional benefits from nuts for body composition measures or glycaemic control. Although improvements in weight loss and glycaemia were not consistent when nuts were included in ER diets, no study revealed an adverse effect of nut consumption on health outcomes. Future studies could explore the effect of consuming different types and amounts of nuts, combined with various levels of energy restriction on weight, body composition and glycaemic control.

Study protocol for a cluster randomized controlled trial for 16 weeks to assess the effect of almond consumption on glycemic control and gut health in prediabetes adults in rural settings of India.. [DOI: 10.1101/2023.06.21.23291579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Introduction

Almonds have prebiotic potential to maintain gut health and regulate glycemia. Western studies have shown their positive effects in preventing non-communicable diseases like diabetes and CVDs. However, there is a lack of well-designed studies involving Asian Indians, who have a higher predisposition to diabetes due to their unique ‘Asian phenotype’. Therefore, this study aims to evaluate the impact of almond supplementation on glycemic control and gut health in prediabetic adults in rural India through a randomized clinical trial.

Methods and Analysis

A parallel cluster randomized controlled trial with 178 prediabetic participants aged 20-50, both genders, with a BMI of 18.9-25 kg/m2, will be conducted in rural areas of Chikkaballapur, Kolar, and rural Bangalore districts in India. The intervention group will receive 56g of almonds as mid-morning snacks for 16 weeks, while the control group will receive cereal pulse based traditional isocaloric snacks under the closed supervision of the study investigators. Anthropometry, clinical, and biochemical parameters will be measured at 0, 8th, and 16th weeks, and a subgroup of 120 participants will undergo gut health analysis. GLP 1 analysis will be conducted on 30 participants at 0 and 16th week. Statistical analysis will be performed using SPSS for Windows V 27.0, and both ITT and per-protocol analyses will be conducted.

Ethics and Dissemination

Ethics approval was obtained from the Institutional Ethics Committee at Ramaiah Medical College, Bangalore, Karnataka, India (DRPEFP7672021). Results from this trial will be disseminated through publication in peer-reviewed journals, national and international presentations.

Trial Registration Number

The trial is registered in the clinical trial registry of India (CTRI/2023/03/050421).

ARTICLE SUMMARY

Strengths and Limitations:

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The study is the first field-based trial in rural settings to assess the effect of almond consumption versus traditional cereal pulse-based snacks on prediabetes adults’ glycemic control and gut health.

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The compliance management is crucially designed by performing an intervention on one-to-one closed supervision, assessment of serum tocopherol levels, and regular follow up of any adverse events.

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The upcoming metagenomic analysis and the gut metabolites like short chain fatty acids (SCFA) and GLP 1 will significantly advance our understanding of the impact of almonds on the gut health of prediabetes adults.

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A potential limitation of the study is that it will not be feasible to follow the participants after the post intervention period.

Acute feeding with almonds compared to a carbohydrate-based snack improves appetite-regulating hormones with no effect on self-reported appetite sensations: a randomised controlled trial

PURPOSE

Early satiety has been identified as one of the mechanisms that may explain the beneficial effects of nuts for reducing obesity. This study compared postprandial changes in appetite-regulating hormones and self-reported appetite ratings after consuming almonds (AL, 15% of energy requirement) or an isocaloric carbohydrate-rich snack bar (SB).

METHODS

This is a sub-analysis of baseline assessments of a larger parallel-arm randomised controlled trial in overweight and obese (Body Mass Index 27.5-34.9 kg/m²) adults (25-65 years). After an overnight fast, 140 participants consumed a randomly allocated snack (AL [n = 68] or SB [n = 72]). Appetite-regulating hormones and self-reported appetite sensations, measured using visual analogue scales, were assessed immediately before snack food consumption, and at 30, 60, 90 and 120 min following snack consumption. A sub-set of participants (AL, n = 49; SB, n = 48) then consumed a meal challenge buffet ad libitum to assess subsequent energy intake. An additional appetite rating assessment was administered post buffet at 150 min.

RESULTS

Postprandial C-peptide area under the curve (AUC) response was 47% smaller with AL compared to SB (p < 0.001). Glucose-dependent insulinotropic polypeptide, glucagon and pancreatic polypeptide AUC responses were larger with AL compared to SB (18%, p = 0.005; 39% p < 0.001; 45% p < 0.001 respectively). Cholecystokinin, ghrelin, glucagon-like peptide-1, leptin and polypeptide YY AUCs were not different between groups. Self-reported appetite ratings and energy intake following the buffet did not differ between groups.

CONCLUSION

More favourable appetite-regulating hormone responses to AL did not translate into better self-reported appetite or reduced short-term energy consumption. Future studies should investigate implications for longer term appetite regulation.

ANZCTR REFERENCE NUMBER

ACTRN12618001861246 2018.

A Comprehensive Review of Almond Clinical Trials on Weight Measures, Metabolic Health Biomarkers and Outcomes, and the Gut Microbiota

This comprehensive narrative review of 64 randomized controlled trials (RCTs) and 14 systematic reviews and/or meta-analyses provides an in-depth analysis of the effect of almonds on weight measures, metabolic health biomarkers and outcomes, and the colonic microbiota, with extensive use of figures and tables. Almonds are a higher energy-dense (ED) food that acts like a lower ED food when consumed. Recent systematic reviews and meta-analyses of nut RCTs showed that almonds were the only nut that had a small but significant decrease in both mean body mass and fat mass, compared to control diets. The biological mechanisms for almond weight control include enhanced displacement of other foods, decreased macronutrient bioavailability for a lower net metabolizable energy (ME), upregulation of acute signals for reduced hunger, and elevated satiety and increased resting energy expenditure. The intake of 42.5 g/day of almonds significantly lowered low-density lipoprotein cholesterol (LDL-C), 10-year Framingham estimated coronary heart disease (CHD) risk and associated cardiovascular disease (CVD) medical expenditures. Diastolic blood pressure (BP) was modestly but significantly lowered when almonds were consumed at >42.5 g/day or for >6 weeks. Recent RCTs suggest possible emerging health benefits for almonds such as enhanced cognitive performance, improved heart rate variability under mental stress, and reduced rate of facial skin aging from exposure to ultraviolet (UV) B radiation. Eight RCTs show that almonds can support colonic microbiota health by promoting microflora richness and diversity, increasing the ratio of symbiotic to pathogenic microflora, and concentrations of health-promoting colonic bioactives. Almonds are a premier healthy snack for precision nutrition diet plans.