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. https://doi.org/10.1017/S0954422424000106


Comparing the Effects of Consuming Almonds or Biscuits on Body Weight in Habitual Snackers: A 1-Year Randomized Controlled Trial

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. https://doi.org/10.1016/j.ajcnut.2023.05.015


Association of legumes and nuts consumption with metabolic health status in Iranian overweight and obese adolescents

Limited data are available on the association of legumes and nuts consumption with health status in pediatrics. So, we assessed the relation of legumes and nuts intake with metabolic health status in Iranian adolescents. A random sample of overweight/obese adolescents aged 12 to 18 years was included in this cross-sectional study. Dietary intakes were gathered using a validated 147-item food frequency questionnaire (FFQ). We measured metabolic indices including blood pressure, lipid profile, glycemic and anthropometrics indices. Two strategies were used for classification of adolescents to metabolically healthy obese (MHO) or unhealthy obese (MUO): International Diabetes Federation (IDF) and combination of IDF with Homeostasis Model Assessment Insulin Resistance (HOMA-IR). Information on 203 overweight/obese adolescents (50.2% girls and 49.8% boys) with an average age of 13.98 (± 1.61) years and a mean weight of 73.48 (± 11.60) kg/m2 was evaluated. Based on the IDF and IDF/HOMA-IR definition, higher consumption of legumes and nuts consumption was related to a 66% and 61% decreased odds of MUO in crude model (OR = 0.34, 95%CI 0.17–0.69), (OR = 0.39, 95%CI 0.19–0.80); but in fully-adjusted model, these relations disappeared. After adjustment for potential cofounders, an inverse association was found between legumes and nuts consumption and odds of hyperglycemia (OR = 0.35, 95%CI 0.16–0.78). Moreover, although inverse significant associations were found between legumes and nuts consumption and odds of MUO in girls and overweight subjects in crude models, these associations disappeared after adjustment for all confounders. After taking potential confounders into account, no significant association was found between consumption of legumes and nuts and MUO in Iranian adolescents. The findings should be affirmed by further prospective studies. https://doi.org/10.1038/s41598-023-32961-2


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

Purpose: Almonds are nutrient-rich, providing a healthier alternative to many snack foods. 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. Taking a pragmatic approach, we compared consumption of almonds versus 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 non-obese habitual discretionary snack consumers to receive almonds or biscuits daily for one-year. 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 months, and body composition and resting metabolic rate at baseline and 12 months. Results: The difference in changes for body weight from baseline to 12 months was not statistically significant (geometric means 67.1 kg and 69.5 kg for almonds and 66.3 kg and 66.3 kg for biscuits, P = 0.275). There were no statistically significant differences in changes for body composition or other non-dietary outcomes (all P ≥ 0.112). Absolute intakes of protein; total, polyunsaturated, and monosaturated fat; fibre; 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), while % TE from carbohydrate and sugar statistically significantly (both P ≤ 0.014) decreased from baseline, in the almond compared to 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 to a popular discretionary snack food. https://doi.org/10.1016/j.ajcnut.2023.05.015


Macadamia nut effects on cardiometabolic risk factors: A randomised trial

We sought to examine the effects of daily consumption of macadamia nuts on body weight and composition, plasma lipids and glycaemic parameters in a free-living environment in overweight and obese adults at elevated cardiometabolic risk. Utilising a randomised cross-over design, thirty-five adults with abdominal obesity consumed their usual diet plus macadamia nuts (~15 % of daily calories) for 8 weeks (intervention) and their usual diet without nuts for 8 weeks (control), with a 2-week washout. Body composition was determined by bioelectrical impedance; dietary intake was assessed with 24-h dietary recalls. Consumption of macadamia nuts led to increased total fat and MUFA intake while SFA intake was unaltered. With mixed model regression analysis, no significant changes in mean weight, BMI, waist circumference, percent body fat or glycaemic parameters, and non-significant reductions in plasma total cholesterol of 2⋅1 % (−4⋅3 mg/dl; 95 % CI −14⋅8, 6⋅1) and low-density lipoprotein (LDL-C) of 4 % (−4⋅7 mg/dl; 95 % CI −14⋅3, 4⋅8) were observed. Cholesterol-lowering effects were modified by adiposity: greater lipid lowering occurred in those with overweight v. obesity, and in those with less than the median percent body fat. Daily consumption of macadamia nuts does not lead to gains in weight or body fat under free-living conditions in overweight or obese adults; non-significant cholesterol lowering occurred without altering saturated fat intake of similar magnitude to cholesterol lowering seen with other nuts. https://doi.org/10.1017/jns.2023.39


Nuts, Energy Balance and Body Weight.

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. https://doi.org/10.3390/nu15051162


The Effects of Tree Nut and Peanut Consumption on Energy Compensation and Energy Expenditure: A Systematic Review and Meta-Analysis.

Nut consumption is not associated with a higher body weight, and potential energy-regulating mechanisms may include a reduced subsequent energy intake and increased EE. The aim of this study was to examine the effect of tree nut and peanut consumption on energy intake, compensation, and expenditure. PubMed, MEDLINE, CINAHL, Cochrane, and Embase databases were searched from inception to June 2, 2021. Human studies with adults aged ≥18 y older were included. Energy intake and compensation studies were restricted to acute effects (intervention duration of ≤24 h), whereas intervention duration was not limited for EE studies. Random effects meta-analyses were conducted to explore weighted mean differences in REE. Twenty-eight articles from 27 studies (16 energy intake studies, 10 EE studies, and 1 study investigating both) with 1121 participants were included in this review, with a variety of nut types addressed (almonds, Brazil nuts, cashews, chestnuts, hazelnuts, peanuts, pistachios, walnuts, and mixed nuts). Energy compensation occurred after nut-containing loads (range: −280.5% to +176.4%) and the degree of compensation varied depending on the form (whole and chopped) and how they were consumed (alone and within a meal). The meta-analyses identified a nonsignificant increase in REE associated with nut consumption (weighted mean difference: 28.6 kcal/d; 95% CI: −10.7, 67.8 kcal/d). This study provided support for energy compensation as a potential mechanism for a lack of association between nut consumption and body weight, whereas no evidence was found for EE as an energy-regulating mechanism of nuts. https://doi.org/10.1016/j.advnut.2022.10.006


Experimental studies and randomised controlled trial investigating the impact of traditional dried fruits consumed as snacks on food intake, experience of appetite and bodyweight.

Two studies investigating the impact of dried fruits eaten as a snack on weight control were designed to examine the effects of prunes and raisins on appetite (phase 1), and whether prunes undermine weight loss, due to the increase in energy density on drying, when included in a structured weight loss programme (phase 2). Phase 1 compared the effect on appetite of equi-weight or equi-caloric snacks of prunes (100 or 140 g) and raisins (100 or 111 g) with a control condition (100 g/335 kcal jelly babies), in a pre-load, cross-over design (n = 40 analysed). A significant effect of condition on food intake was observed, with significantly lower weight of food consumed in the 140 g prune group versus control, and on Area Under the Curve (AUC) fullness, due to a greater effect in the 140 g prune group versus control. In phase 2, change in bodyweight and waist circumference were measured in a 12-week randomised, parallel-groups intervention study (n = 100 analysed, 50 per group). Prunes (females: 140 g, males: 171 g/day) replaced usual snacks whilst following a weight loss programme. The active control group followed the same programme and participants were instructed on healthy snacking. A significant reduction in mean bodyweight in the prune group versus baseline was consistent with the phase 1 evidence that prunes can aid appetite control, although it could also be explained by overall diet in the context of a structured weight loss programme. Prunes did not produce a detrimental effect on mean weight loss over 12 weeks versus control (prune group: −1.99 kg; active control: −1.53 kg), nor on decrease in waist circumference (prune group: −2.40 cm; active control: −1.74 cm). No additional benefit on weight loss was seen (between-group difference was non-significant). The daily intake of prunes was well-tolerated. Phase 1 demonstrated that prune snacks produced beneficial changes in appetite. Phase 2 demonstrated that prunes did not undermine weight management, and this warrants further study. https://doi.org/10.1111/nbu.12528

Acute consumption of a shake containing cashew and Brazil nuts did not affect appetite in overweight subjects: a randomized, cross-over study.

Purpose. Evidence from epidemiological and clinical studies suggests that nut consumption provides satiety and may contribute to the management of obesity. However, the effect of acute intake of nuts on appetite responses remains unclear. The objective of this study was to evaluate the acute effect of a shake containing 30 g of cashew nuts (Anacardium occidentale L.) and 15 g of Brazil nuts (Bertholletia excelsa H.B.K) on appetite responses in overweight subjects. Methods. This was a clinical, randomized, controlled, single-blind, cross-over, pilot study. On two non-consecutive test days, 15 subjects received a shake containing nuts, and a shake absent of nuts matched for energy and macronutrient content. Subjective appetite sensation was evaluated by visual analogue scales (VAS). Food intake was measured by weighing the lunch served at the end of each morning-test, which subjects ate ad libitum. Total energy intake was estimated by food records. This study is registered on the Brazilian Registers of Clinical Trials—ReBEC (protocol: U1111-1203-9891). Results. We observed no significant difference in subjective appetite sensations between the groups. Food intake at lunch, as well as energy intake throughout the day also did not differ between the treatments. Conclusion. Our results suggest that the acute intake of a shake containing nuts was not able to enhance satiety, compared to a shake matched for energy and macronutrient content. Further studies are warranted to elucidate the satiety mechanisms of nuts intake. https://doi.org/10.1007/s00394-021-02560-w


Nut consumption, body weight, and adiposity in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.

Context. It seems that nut consumption does not lead to weight gain in the general population. However, fewer studies have explored this relationship in individuals with type 2 diabetes (T2D). Purpose. To synthesize evidence on the effects of nut (specifically, tree nuts and peanuts) consumption on adiposity-related measures in individuals diagnosed with T2D. Data Sources and Study Selection. Four databases were searched up to December 31, 2020. Randomized controlled trials that examined the effects of nut consumption vs a control diet on body weight, body mass index, waist circumference, and percent body fat were included. Data Extraction. The pooled effect sizes (p-ESs) and 95%CIs of nut consumption were estimated using random effects models. Data Synthesis. A total of 15 randomized controlled trials including 899 individuals were included. No significant effects of nut-enriched interventions were found for body weight (p-ES = −0.04; 95%CI: −0.16 to 0.08), body mass index (p-ES = −0.05; 95%CI: −0.17 to 0.08), waist circumference (p-ES = −0.02; 95%CI: −0.20 to 0.15), or percent body fat (p-ES = −0.03; 95%CI: −0.28 to 0.21). Conclusion. Nut consumption has no effect, positive or negative, on weight or adiposity parameters in people with T2D. https://doi.org/10.1093/nutrit/nuab053