Higher visceral adiposity is associated with an enhanced early thermogenic response to carbohydrate-rich food

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. This review was registered at PROSPERO as CRD42021252292.

Effects of acute and chronic nuts consumption on energy metabolism: a systematic review of randomised clinical trials

Nuts are high-energy density foods and are associated with beneficial effects on health, including weight control. Effects on resting energy expenditure, respiratory quotient, and diet-induced thermogenesis are suggested mechanisms behind the effects of nuts consumption on weight control. Thus, we revised the randomised clinical trials that assessed acute and chronic nuts consumption effects on energy metabolism. Walnuts (22.1 g to 56 g) consumption appears to modulate energy metabolism markers differently depending on the dose and profile of the evaluated subject. In its turn, 56 g of high-oleic peanuts increased postprandial energy expenditure and thermic effect of food after three hours postprandial compared to consumption of conventional peanuts. Almonds, hazelnuts, peanuts, and a mix of nuts were the nuts studies in the chronic studies, which does not seem to influence energy metabolism markers. Further studies are needed to elucidate the effects of other types of nuts consumption on energy metabolism.

Causal relationship between dietary macronutrient composition and anthropometric measures: A bidirectional two-sample Mendelian randomization analysis

BACKGROUND

The question whether the proportion of energy provided by fat and carbohydrates in the diet is associated with body mass index (BMI) and waist circumference (WC) is an important public health issue, but determining causality is difficult in epidemiological studies.

OBJECTIVES

Using a two-sample bidirectional Mendelian randomization (MR) in both a univariable and multivariable setting, we aimed to determine whether the relative proportion of different macronutrients in the diet (in % of total energy intake (E%)) is causally related to BMI and WC and vice versa.

METHODS

All analyses were based on genome-wide association studies including 268,922 Europeans with dietary data (SSGAC Consortium) and at least 232,101 with anthropometric measures (GIANT Consortium). An inverse-variance weighted approach using modified second-order weights within the radial regression framework was performed. Radial MR-Egger, weighted median and mode, Robust Adjusted Profile Score (RAPS), and Pleiotropy RESidual Sum and Outlier (PRESSO) methods were used in sensitivity analyses to verify MR assumptions. Additionally, multivariable MR was conducted to account for inter correlation between macronutrient intakes. All estimates represent the standard deviation (SD) change in each outcome per one SD change in the respective exposure.

RESULTS

We found that genetically predicted relative carbohydrate intake (E%) reduced BMI (β = -0.529; 95% CI: -0.745, -0.312; P-value = 2⋅10^-6) and WC (β = -0.459; 95% CI: -0.656, -0.262; P-value = 5⋅10^-6). Both effects were also supported by the multivariable approach: β = -0.441 (95% CI: -0.772, -0.109; P-value = 0.009) for BMI and β = -0.410 (95% CI: -0.667, -0.154; P-value = 0.002) for WC. Genetically predicted dietary intake of fat (E%) was weaker and positively related to both anthropometric measures. We obtained evidence that a higher BMI and WC increased the relative dietary intake of fat and protein (E%). For example, each SD higher BMI increased protein intake (E%) by 0.114 SD (95% CI: 0.081, 0.147; P-value = 9⋅10^-12) and each SD higher WC increased protein intake (E%) by 0.078 SD (95% CI: 0.035, 0.121; P-value = 4⋅10^-4). Sensitivity analyses confirmed these findings revealing consistent effect estimates.

CONCLUSIONS

Using genetic information to improve causal inference we found evidence, that a low relative carbohydrate proportion (E%) and a high proportion of fat (E%) in the diet is causally related to a higher BMI and a higher WC. Further research considering carbohydrate, fat, and protein quality and possible consequences on micronutrient intake is needed to define the implications for dietary intake recommendations.

Dietary Factors and Eating Behaviors Affecting Diet-Induced Thermogenesis in Obese Individuals: A Systematic Review

Obese individuals are considered to have lower energy expenditure (EE) rates than non-obese individuals. We aimed to investigate the effects of various factors related to food intake on diet-induced thermogenesis (DIT) in the EE of obese individuals. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we reviewed relevant literature from PubMed, Embase, and Medline databases from study inception till the end of July 2019. Studies on dietary factors affecting DIT in obese individuals were included. Fifteen studies were included; these studies assessed macronutrient, single-nutrient, or supplement meal compositions, as well as dietary patterns and behaviors. The effect of obesity on DIT was not constant in each study. Differences in DIT pertained to the protein ratio being higher than the fat ratio or the carbohydrate ratio being higher than the fat ratio. High intake of calcium and vitamin D as well as high-oleic peanut supplements increased DIT in obese people. In addition, ascorbic acid intake, fatty acid saturation, and the chain length of various fatty acids had no effects on DIT. In conclusion, the findings suggest that in obese individuals, DIT is associated with various factors related to meal, nutrient, and dietary habits. However, because of the complexity of the relationship between DIT and obesity, it is difficult to determine the critical element underlying this association.

Intramyocellular triacylglycerol accumulation across weight loss strategies; Sub-study of the CENTRAL trial

BACKGROUND

Intramyocellular triacylglycerol (IMTG) is utilized as metabolic fuel during exercise and is linked to insulin resistance, but the long-term effect of weight loss strategies on IMTG among participants with abdominal fat, remain unclear.

METHODS

In an 18-month trial, sedentary participants with abdominal fat/dyslipidemia were randomized to either a low-fat (LF) or Mediterranean/low-carbohydrate (MED/LC) diet (including 28g·day-1 of walnuts). After 6-months, the participants were re-randomized to moderate intense physical activity (PA+) or non-physical activity (PA-). Magnetic resonance imaging (MRI) was used to quantify changes of IMTG, abdominal sub-depots, hepatic and intermuscular fats.

RESULTS

Across the 277 participants [86% men, age = 48 years, body-mass-index (BMI) = 31kg/m2, visceral fat = 33%] 86% completed the 18-m trial. At baseline, women had higher IMTG than men (3.4% vs. 2.3%, p<0.001) and increased IMTG was associated with aging and higher BMI, visceral and intermuscular fats, HbA1c%, HDL-c and leptin(p<0.05), but not with intra-hepatic fat. After 18 month of intervention and a -3 kg mean weight loss, participants significantly increased IMTG by 25%, with a distinct effect in the MED/LCPA+ group as compared to the other intervention groups (57% vs. 9.5-18.5%, p<0.05). Changes in IMTG were associated with visceral and intermuscular fat, metabolic syndrome, insulin and leptin (p<0.05 for all), however, these associations did not remain after adjustment for visceral fat changes.

CONCLUSIONS

Lifestyle strategies differentially affect IMTG accumulation; combination of exercise with decreased carbohydrate/increased unsaturated fat proportion intake greatly increase IMTG. Our findings suggest that increased IMTG during diet-induced moderate weight loss may not be directly related to cardiometabolic risk.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01530724.

The effect of fertility treatment on adverse perinatal outcomes in women aged at least 40 years

OBJECTIVE

To compare perinatal outcomes between spontaneous conception and assisted reproductive technologies (ART) among patients of advanced maternal age.

METHODS

The present retrospective study included data from singleton pregnancies of women aged at least 40 years who delivered between January 1, 1991, and December 31, 2013, at Soroka University Medical Center, Beer Sheva, Israel. Demographic, obstetric, and perinatal data were compared between pregnancies conceived with ART (in vitro fertilization [IVF] or ovulation induction) and those conceived spontaneously. Multiple regression models were used to define independent predictors of adverse outcomes.

RESULTS

A total of 8244 singleton pregnancies were included; 229 (2.8%) following IVF, 86 (1.0%) following ovulation induction, and 7929 (96.2%) were spontaneous. Preterm delivery (P<0.001), fetal growth restriction (FGR) (P<0.001), and cesarean delivery (P<0.001) demonstrated linear associations with the conception mode; the highest rates for each were observed for IVF, with decreased rates for ovulation induction and spontaneous conception. The incidence of gestational diabetes and hypertensive disorders were highest among pregnancies following ART. No association was observed between conception mode and perinatal mortality. Multivariate logistic regression demonstrated that IVF was independently associated with increased odds of preterm delivery (P<0.001) and FGR (P=0.027) compared with spontaneous conception.

CONCLUSIONS

Among patients of advanced maternal age, ART were independently associated with increased FGR and preterm delivery rates compared with spontaneous pregnancies; perinatal mortality was comparable.

Dynamics of intrapericardial and extrapericardial fat tissues during long-term, dietary-induced, moderate weight loss

Background: In view of evidence linking pericardial fat accumulation with increased cardiovascular disease risk, strategies to reduce its burden are needed. Data comparing the effects of specific long-term dietary interventions on pericardial fat tissue mobilization are sparse.Objective: We sought to evaluate intrapericardial-fat (IPF) and extrapericardial-fat (EPF) changes during weight-loss interventions by different dietary regimens.Design: During 18 mo of a randomized controlled trial, we compared a Mediterranean/low-carbohydrate (MED/LC) diet plus 28 g walnuts/d with a calorically equal low-fat (LF) diet among randomly assigned participants with moderate abdominal obesity. We performed whole-body MRI and volumetrically quantified IPF and EPF among 80 participants to follow the 18-mo changes.Results: The participants [mean age: 48.6 y; mean body mass index (BMI; in kg/m²); 31.7; 90% men] had baseline IPF and EPF (mean ± SD) volumes of 172.4 ± 53.3 mL and 194.9 ± 71.5 mL, respectively. The 18-mo moderate weight loss of 3.7 kg was similar in both groups, but the reduction in waist circumference was higher in the MED/LC group (-6.9 ± 6.6 cm) than in the LF diet group (-2.3 ± 6.5 cm; P = 0.01). After 18 mo, the IPF volume had reduced twice as much in the MED/LC group compared with the LF group [-37 ± 26.2 mL (-22% ± 15%) compared with -15.5 ± 26.2 mL (-8% ± 15%), respectively; P < 0.05, after adjustment for changes in weight or visceral adipose tissue]. The EPF volume had reduced similarly in both groups [-41.6 ± 30.2 mL (-23% ± 16%) in the MED/LC group compared with -37.9 ± 28.3 mL (-19% ± 14%) in the LF group; P > 0.1]. After controlling for weight loss, IPF and EPF volume reduction paralleled changes in lipid profile but not with improved glycemic profile variables: the IPF relative reduction was associated with a decrease in triglycerides (TGs) (β = 0.090; 95% CI: 0.026, 0.154; P = 0.007) and the ratio of TGs to high-density lipoprotein (HDL) cholesterol (β = 2.689; 95% CI: 0.373, 5.003; P = 0.024), and the EPF relative reduction was associated with an increase in HDL cholesterol (β = -0.452; 95% CI: -0.880, -0.023; P = 0.039) and a decrease in total cholesterol and HDL cholesterol (β = 3.766; 95% CI: 1.092, 6.440; P = 0.007).Conclusions: Moderate but persistent dietary-induced weight loss substantially decreased both IPF and EPF volumes. Reduction of pericardial adipose tissues is independently associated with an improved lipid profile. The Mediterranean diet, rich in unsaturated fats and restricted carbohydrates, is superior to an LF diet in terms of the IPF burden reduction. This trial was registered at clinicaltrials.gov as NCT01530724.

Altered Metabolic Homeostasis in Amyotrophic Lateral Sclerosis: Mechanisms of Energy Imbalance and Contribution to Disease Progression

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the death of motor neurones, which leads to paralysis and death in an average of 3 years following diagnosis. The cause of ALS is unknown, but there is substantial evidence that metabolic factors, including nutritional state and body weight, affect disease progression and survival. This review provides an overview of the characteristics of metabolic dysregulation in ALS focusing on mechanisms that lead to disrupted energy supply (at a whole-body and cellular level) and altered energy expenditure. We discuss how a decrease in energy supply occurs in parallel with an increase in energy demand and leads to a state of chronic energy deficit which has a negative impact on disease outcome in ALS. We conclude by presenting potential and tested strategies to compensate for, or correct this energy imbalance, and speculate on promising areas for further research.

Abdominal fat sub-depots and energy expenditure: Magnetic resonance imaging study

BACKGROUND & AIMS

We aimed to assess the association between the distinct abdominal sub-depots and resting energy expenditure (REE).

METHODS

We performed magnetic resonance imaging (MRI) to quantify abdominal visceral-adipose-tissue (VAT), deep-subcutaneous-adipose-tissue (deep-SAT), and superficial-subcutaneous-adipose-tissue (superficial-SAT). We measured REE by indirect-calorimetry. Non-exercise activity thermogenesis (NEAT) [1-3 metabolic equivalents (METs)] and exercise thermogenesis (activities of 4+MET_S) were estimated based on 6-days of accelerometry to assess total physical activity energy expenditure (PAEE).

RESULTS

We studied 282 participants: 249 men [mean age = 47.4 years, body-mass-index (BMI) = 31 kg/m², mean VAT proportion from total abdominal fat = 34.5%, mean superficial-SAT proportion from total abdominal fat = 24.3%] and 33 women (mean age = 51.2 years, BMI = 30.1 kg/m², mean VAT proportion from total abdominal fat = 22.8%, mean superficial-SAT proportion from total abdominal fat = 37.8%). As expected, women had lower REE [by 32.4% (1488 ± 234 kcal/day vs. 1971 ± 257 kcal/day; p < 0.01)] and lower REE/kg [by 8% (19.6 ± 3 kcal/kg vs. 21.2 ± 2 kcal/kg; p < 0.01)] than men. Exercise and total PAEE were positively associated with REE/kg (p < 0.01 for both) and a positive correlation between NEAT and REE/kg was borderline (p = 0.056). Participants, in whom abdominal VAT was the dominant proportional depot, had higher REE (1964 ± 297 kcal/day vs. 1654 ± 352 kcal/day; p < 0.01) and higher REE∖kg (22.2 ± 2.3 kcal/kg/day vs. 19.6 ± 2.5 kcal/kg/day; p < 0.01) than participants in whom superficial-SAT was the largest proportional depot. In multivariate models, adjusted for age, gender and residual BMI, increased VAT proportion was independently associated with higher REE (β = 0.181; p = 0.05). Likewise, increased VAT proportion (β = 0.482; p < 0.01) remained independently associated with higher REE/kg. In this model younger age (β = -0.329; p < 0.01) was associated with higher REE/kg.

CONCLUSIONS

Abdominal fat distribution patterns are associated with varying levels of resting energy expenditure, potentially reflecting different metabolic rates of adipose sub-depots and providing an anatomic/anthropometric link to physiological obese sub-phenotypes.