Archive

Research Area: Body Weight/Satiety

Consumption of tree nuts as snacks reduces metabolic syndrome risk in young adults: a randomized trial.

Sumislawski, K., A. Widmer, R.R. Suro, M.E. Robles, K. Lillegard, D. Olson, J.R. Koethe, H.J. Silver, 2023. Consumption of tree nuts as snacks reduces metabolic syndrome risk in young adults: a randomized trial. Nutrients. 15(24):5051. doi: 10.3390/nu15245051.

Metabolic syndrome (MetSx) and its chronic disease consequences are major public health concerns worldwide. Between-meal snacking may be a modifiable risk factor. We hypothesized that consuming tree nuts as snacks, versus typical carbohydrate snacks, would reduce risk for MetSx in young adults. A prospective, randomized, 16-week parallel-group diet intervention trial was conducted in 84 adults aged 22-36 with BMI 24.5 to 34.9 kg/m2 and ≥1 MetSx clinical risk factor. Tree nuts snacks (TNsnack) were matched to carbohydrate snacks (CHOsnack) for energy (kcal), protein, fiber, and sodium content as part of a 7-day eucaloric menu. Difference in change between groups was tested by analysis of covariance using general linear models. Multivariable linear regression modeling assessed main effects of TNsnack treatment and interactions between TNsnack and sex on MetSx score. Age, BMI, and year of study enrollment were included variables. There was a main effect of TNsnack on reducing waist circumference in females (mean difference: -2.20 ± 0.73 cm, p = 0.004) and a trend toward reduced visceral fat (-5.27 ± 13.05 cm2, p = 0.06). TNsnack decreased blood insulin levels in males (-1.14 ± 1.41 mIU/L, p = 0.05) and multivariable modeling showed a main effect of TNsnack on insulin. Main effects of TNsnack on triglycerides and TG/HDL ratio were observed (p = 0.04 for both) with TG/HDL ratio reduced ~11%. A main effect of TNsnack (p = 0.04) and an interaction effect between TNsnack and sex (p < 0.001) on total MetSx score yielded 67% reduced MetSx score in TNsnack females and 42% reduced MetSx score in TNsnack males. To our knowledge, this is the first randomized parallel-arm study to investigate cardiometabolic responses to TNsnacks versus typical CHOsnacks among young adults at risk of MetSx. Our study suggests daily tree nut consumption reduces MetSx risk by improving waist circumference, lipid biomarkers, and/or insulin sensitivity-without requiring caloric restriction.

Comparing the effects of consuming almonds or biscuits on body weight in habitual snackers: a 1-year randomized controlled trial. 

Brown, R. C., L. Ware, A.R. Gray, S.L. Tey, A. Chisholm, 2023. Comparing the effects of consuming almonds or biscuits on body weight in habitual snackers: a 1-year randomized controlled trial. Amer. J. Clin. Nutr. 118(1):228–240. https://doi.org/10.1016/j.ajcnut.2023.05.015

Background: Almonds are nutrient rich, providing a healthier alternative to many snacks. Studies report health benefits with regular almond consumption without adverse weight gain. However, most interventions have been relatively short or have included additional dietary advice. Objectives: Taking a pragmatic approach, we compared consumption of almonds compared with biscuits on body weight and other health outcomes in a population of regular snackers of discretionary foods, hypothesizing the almonds will displace some of the less-healthful snacks in their current diets. Methods: We randomly assigned 136 nonobese habitual discretionary snackers to receive almonds or biscuits daily for 1 y. These isocaloric snacks provided either 10% of participants’ total energy (TE) requirements or 1030 kJ (equivalent to 42.5 g almonds), whichever was greater. Anthropometry, blood biomarkers, diet, appetite, sleep, and physical activity were assessed at baseline, 3, 6, and 12 mo, and body composition and RMR at baseline and 12 mo. Results: The difference in changes for body weight from baseline to 12 mo was not statistically significant (geometric means: 67.1 and 69.5 kg for almonds and 66.3 and 66.3 kg for biscuits, P = 0.275). There were no statistically significant differences in changes for body composition or other nondietary outcomes (all P ≥ 0.112). Absolute intakes of protein; total, polyunsaturated, and monosaturated fat; fiber; vitamin E; calcium; copper; magnesium; phosphorous; and zinc, and % TE from total monounsaturated, and polyunsaturated fat statistically significantly increased from baseline (all P ≤ 0.033), whereas % TE from carbohydrate and sugar statistically significantly (both P ≤ 0.014) decreased from baseline, in the almond compared with the biscuit group. Conclusions: Almonds can be incorporated into the diets of habitual snackers to improve diet quality, without evidence for changes in body weight, compared with a popular discretionary snack food.

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. 

Carter, S., A.M. Hill, J.D. Buckley, S.Y. Tan, G.B. Rogers, A.M. Coates, 2023. 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. Eur. J. Nutr. 62(2):857–866. https://doi.org/10.1007/s00394-022-03027-2

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.

Almonds vs. carbohydrate snacks in an energy-restricted diet: Weight and cardiometabolic outcomes from a randomized trial. 

Carter, S., A.M. Hill, L.C. Mead, H.Y. Wong, C. Yandell, J.D. Buckley, S.Y. Tan, G.B. Rogers, F. Fraysse, A.M. Coates, 2023. Almonds vs. carbohydrate snacks in an energy-restricted diet: Weight and cardiometabolic outcomes from a randomized trial. Obesity 31(10):2467–2481.

Objective: This study evaluated weight and cardiometabolic outcomes after a 3-month energy-restricted diet (-30%) containing almonds (almond-enriched diet [AED]) or containing carbohydrate-rich snacks (nut-free control diet [NFD]) (Phase 1), followed by 6 months of weight maintenance (Phase 2). Methods: Participants (25-65 years old) with overweight or obesity (BMI 27.5-34.9 kg/m2 ) were randomly allocated to AED (n = 68) or NFD (n = 72). Results: Both groups lost weight during Phase 1 (p < 0.001) (mean [SE], -7.0 [0.5] kg AED vs. -7.0 [0.5] kg NFD, p = 0.858) and Phase 2 (p = 0.009) (-1.1 [0.5] kg AED vs. -1.3 [0.6] NFD, p = 0.756), with improvements in percentage lean mass after Phase 2 (4.8% [0.3%], p < 0.001). Reductions occurred in fasting glucose (-0.2 [0.07] mmol/L, p = 0.003), insulin (-8.1 [4.0] pmol/L, p = 0.036), blood pressure (-4.9 [0.8] mm Hg systolic, -5.0 [0.5] mm Hg diastolic, p < 0.001), total cholesterol (-0.3 [0.1] mmol/L), low-density lipoprotein (LDL) (-0.2 [0.1] mmol/L), very low-density lipoprotein (-0.1 [0.03] mmol/L), and triglycerides (-0.3 [0.06] mmol/L) (all p < 0.001), and high-density lipoprotein increased (0.1 [0.02] mmol/L, p = 0.011) by the end of Phase 2 in both groups. There were group by time interactions for lipoprotein particle concentrations: very small triglyceride-rich (-31.0 [7.7] nmol/L AED vs. -4.8 [7.9] nmol/L NFD, p = 0.007), small LDL (-109.3 [40.5] nmol/L AED vs. -20.7 [41.6] nmol/L NFD, p = 0.017), and medium LDL (-24.4 [43.4] nmol/L AED vs. -130.5 [44.4] nmol/L NFD, p = 0.045). Conclusions: An energy-restricted AED resulted in weight loss and weight loss maintenance comparable to an energy-restricted NFD, and both diets supported cardiometabolic health. The AED resulted in greater improvements in some lipoprotein subfractions, which may enhance reductions in cardiovascular risk.

Premeal almond load decreases postprandial glycaemia, adiposity and reversed prediabetes to normoglycemia: a randomized controlled trial. 

Gulati, S., A. Misra, R. Tiwari, M. Sharma, R.M. Pandey, A.D. Upadhyay, H. Chandra Sati, 2023. Premeal almond load decreases postprandial glycaemia, adiposity and reversed prediabetes to normoglycemia: a randomized controlled trial. Clinical nutrition ESPEN, 54, 12–22. https://doi.org/10.1016/j.clnesp.2022.12.028

Background: Asian Indians show rapid conversion from prediabetes to type 2 diabetes (T2D). Novel dietary strategies are needed to arrest this progression, by targeting postprandial hyperglycaemia (PPHG). Design: We conducted a free-living randomized controlled open-label parallel arm study to evaluate the effect of a premeal load of almonds (20 g) 30 min before major meals on anthropometric, glycaemic, and metabolic parameters over 3 months. Sixty-six participants with prediabetes in the age range of 18-60 yrs were recruited. The study was registered at clinicaltrials.gov (registration no. NCT04769726). Results: Thirty participants in each arm completed the study. As per ‘intention-to-treat’ analysis, overall additional mean reductions were statistically significant for body weight, BMI, waist circumference (WC), subscapular and suprailiac skinfolds, and improved handgrip strength (Kg) (p < 0·001 for all) in the treatment arm vs. the control arm (after multiple adjustments). In the blood parameters, the additional mean reduction in the treatment arm vs. control arm was statistically significant for fasting and post-75 g oral glucose-load blood glucose, postprandial insulin, HOMA-IR, HbA1c, proinsulin, total cholesterol, and very low-density lipoprotein cholesterol (p < 0·001 for all). Most importantly, we observed a reversal to normoglycemic state (fasting blood glucose and 2 h post-OGTT glucose levels) in 23.3% (7 out of 30) of participants in the treatment arm which is comparable to that seen with Acarbose treatment (25%). Conclusion: Incorporation of 20 g of almonds, 30 min before each major meal leads to significant improvement in body weight, WC, glycemia (particularly PPHG), and insulin resistance and shows potential for reversal of prediabetes to normal glucose regulation over 3 months.

Keywords: Almonds; Asian Indians; Postprandial glucose regulators; Postprandial hyperglycaemia; Prediabetes.

Effect of almond consumption on insulin sensitivity and serum lipids among Asian Indian adults with overweight and obesity- A randomized controlled trial.

Gayathri, R., K. Abirami, N. Kalpana, V.S. Manasa, V. Sudha, S. Shobana, R.G. Jeevan, V. Kavitha, K. Parkavi, R.M. Anjana, R. Unnikrishnan, K. Gokulakrishnan, D.A. Beatrice, K. Krishnaswamy, R. Pradeepa, R.D. Mattes, J. Salas-Salvadó, W. Willett, V. Mohan, 2023. Effect of almond consumption on insulin sensitivity and serum lipids among Asian Indian adults with overweight and obesity- A randomized controlled trial. Front. Nutr. 9: 1055923. https://doi.org/10.3389/fnut.2022.1055923

Background: Asian Indians have an increased susceptibility to type 2 diabetes and premature coronary artery disease. Nuts, like almonds, are rich in unsaturated fat and micronutrients with known health benefits. Objectives: This study aimed to assess the efficacy of almonds for reduction of insulin resistance and improving lipid profile in overweight Asian Indian adults. Methods: This parallel-arm, randomized, controlled trial was conducted in Chennai, India on 400 participants aged 25-65 years with a body mass index ≥ 23 kg/m2. The intervention group received 43 g of almonds/day for 12 weeks, while the control group was advised to consume a customary diet but to avoid nuts. Anthropometric, clinical, and dietary data were assessed at periodic intervals. Glucose tolerance, serum insulin, glycated hemoglobin, C-peptide and lipid profile were assessed at baseline and end of the study. Insulin resistance (homeostasis assessment model-HOMA IR) and oral insulin disposition index (DIo) were calculated. Results: A total of 352 participants completed the study. Significant improvement was seen in DIo [mean (95% CI) = + 0.7 mmol/L (0.1, 1.3); p = 0.03], HOMA IR (-0.4 (-0.7, -0.04; p = 0.03) and total cholesterol (-5.4 mg/dl (-10.2, -0.6); p = 0.03) in the intervention group compared to the control group. Incremental area under the curve (IAUC) and mean amplitude of glycemic excursion (MAGE) assessed using continuous glucose monitoring systems were also significantly lower in the intervention group. Dietary 24-h recalls showed a higher significant reduction in carbohydrate and increase in mono unsaturated fatty acid (MUFA) and polyunsaturated fatty acids (PUFA) intake in the intervention group compared to the control group. Conclusion: Daily consumption of almonds increased the intake of MUFA with decrease in carbohydrate calories and decreases insulin resistance, improves insulin sensitivity and lowers serum cholesterol in Asian Indians with overweight/obesity. These effects in the long run could aid in reducing the risk of diabetes and other cardiometabolic disease.

Long-term consumption of nuts (including peanuts, peanut butter, walnuts, and other nuts) in relation to risk of frailty in older women: evidence from a cohort study.

Wang, R., M.T. Hannan, M. Wang, A.W. Schwartz, E. Lopez-Garcia, F. Grodstein, 2023. Long-term consumption of nuts (including peanuts, peanut butter, walnuts, and other nuts) in relation to risk of frailty in older women: evidence from a cohort study. J. Nutr. 153(3): 820–827.

Background: Adherence to a healthy diet is inversely associated with frailty. However, the relationship between nuts, a key food group of Mediterranean diet, and frailty is unclear. Objectives: This study aimed to evaluate the association between nut consumption and frailty in an aging female population. Methods: This population-based observational study included nonfrail women (60 y old) in the NHS from 11 states of the United States.

Outcome was incident frailty, defined as having 3 of the FRAIL components (fatigue, lower strength, reduced aerobic capacity, multiple chronic conditions, and significant weight loss) and assessed every 4 y from 1992 to 2016. From 1990 to 2014, FFQs were used to assess the intakes of peanuts, peanut butter, walnuts (added in 1998), and other nuts at 4-y intervals. Exposure was total nut consumption, calculated as the sum of intakes of peanuts, peanut butter, walnuts, and other nuts and categorized into <1 serving/mo, 1–3 servings/mo, 1 serving/wk, 2 4 servings/wk, and 5 servings/wk. The relations of intakes of peanuts, peanut butter, and walnuts with frailty were also investigated separately. Cox proportional hazards models were used to assess the associations between nut consumption and frailty after adjusting for age, smoking, BMI, EI, diet quality, and medication use. Results: Among 71,704 participants, 14,195 incident frailty cases occurred over 1,165,290 person-years. The adjusted HR (95% CI) for consuming 5 servings/wk of nuts was 0.80 (0.73, 0.87), as compared with <1 serving/mo. Higher intakes of peanuts and walnuts, but not peanut butter, were also inversely associated with frailty. Conclusions: This large prospective cohort study showed a strong and consistent inverse association between regular nut consumption and incident frailty. This suggests that nut consumption should be further tested as a convenient public health intervention for the preservation of health and well-being in older adults.

Nuts, Energy Balance and Body Weight.

Baer, D.J., M. Dalton, J. Blundell, G. Finlayson, F.B. Hu, 2023. Nuts, Energy Balance and Body Weight. Nutrients. 15(5):1162. doi: 10.3390/nu15051162.

Over several decades, the health benefits of consuming nuts have been investigated, resulting in a large body of evidence that nuts can reduce the risk of chronic diseases. The consumption of nuts, being a higher-fat plant food, is restricted by some in order to minimize weight gain. In this review, we discuss several factors related to energy intake from nuts, including food matrix and its impact on digestibility, and the role of nuts in regulating appetite. We review the data from randomized controlled trials and observational studies conducted to examine the relationship between nut intake and body weight or body mass index. Consistently, the evidence from RCTs and observational cohorts indicates that higher nut consumption does not cause greater weight gain; rather, nuts may be beneficial for weight control and prevention of long-term weight gain. Multiple mechanisms likely contribute to these findings, including aspects of nut composition which affect nutrient and energy availability as well as satiety signaling.

Mixed nuts as healthy snacks: effect on tryptophan metabolism and cardiovascular risk factors.

Yang, J., R. Lee, Z. Schulz, A. Hsu, J. Pai, S. Yang, S.M. Henning, J. Huang, J.P. Jacobs, D. Heber, Z. Li., 2023. Mixed nuts as healthy snacks: effect on tryptophan metabolism and cardiovascular risk factors. Nutrients. 15, 569; https://doi.org/10.3390/nu15030569.

We recently demonstrated that the consumption of mixed tree nuts (MTNs) during caloric restriction decreased cardiovascular risk factors and increased satiety. Tryptophan (Trp) metabolism has been indicated as a factor in cardiovascular disease. Here, we investigated the effect of MTNs on Trp metabolism and the link to cardiovascular risk markers. Plasma and stool were collected from 95 overweight individuals who consumed either MTNs (or pretzels) daily as part of a hypocaloric weight loss diet for 12 weeks followed by an isocaloric weight maintenance program for an additional 12 weeks. Plasma and fecal samples were evaluated for Trp metabolites by LC–MS and for gut microbiota by 16S rRNA sequencing. Trp–kynurenine metabolism was reduced only in the MTNs group during weight loss (baseline vs. week 12). Changes in Trp–serotonin (week 24) and Trp–indole (week 12) metabolism from baseline were increased in the MTNs group compared to the pretzel group. Intergroup analysis between MTN and pretzel groups does not identify significant microbial changes as indicated by alpha diversity and beta diversity. Changes in the relative abundance of genus Paludicola during intervention are statistically different between the MTNs and pretzel group with p < 0.001 (q = 0.07). Our findings suggest that consumption of MTNs affects Trp host and microbial metabolism in overweight and obese subjects.

The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial.

Zelicha, H., N. Kloting, A. Kaplan, A. Yaskolka Meir, E. Rinott, G. Tsaban, Y. Chassidim,  M. Bluher, U. Ceglarek, B. Isermann, M. Stumvoll, R.N. Quayson, M. von Bergen, B. Engelmann, U.E. Rolle-Kampczyk, S.B. Haange, K.M. Tuohy, C. Diotallevi, I. Shelef, F.B. Hu, M.J. Stampfer, I. Shai, 2022. The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial. BMC Medicine. 20(1):327. https://doi.org/10.1186/s12916-022-02525-8

Background: Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). Methods: In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3–4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. Results: Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: − 2.7%, green-MED: − 3.9%) and waist circumference (MED: − 4.7%, green-MED: − 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: − 4.2%, MED: − 6.0%, green-MED: − 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). Conclusions: A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression.