Neuroimaging studies have identified lower activation in the left dorsolateral PFC (DLPFC) in obese compared to lean individuals and others have focused on efforts to improve cognitive control in this area of the brain. The DLPFC is a critical brain area associated with appetitive control, food craving, and executive functioning, indicating a candidate target area for treatment. Further studies are needed to advance our understanding of the relationship between obesity, appetite, and the DLPFC and provide validation for the effectiveness of novel treatments in clinical populations.

Objective: The association between food insecurity and obesity may be partially explained by overeating in response to unpredictable food availability cycles. The aim of this study was to measure objective food intake in food insecure individuals. Methods: 82 volunteers (53m; BMI 29±7; 38±12y) were admitted to our inpatient Clinical Research Unit and completed the Food Security Short Form (FSSF), Three-Factor Eating Questionnaire and Gormally Binge Eating Scale and body composition assessment (DXA). After 5d of weight maintaining diet, participants self-selected food from an ad libitum vending machine paradigm for 3d. Mean daily intake (kcal), macronutrient intake, and percentage of weight maintaining energy needs (%WMEN) were calculated. Results: Based on FSSF cutoffs, food insecure participants (n=46; 56%) had higher body weight ( p =.04), FFM ( p =.05), disinhibition ( p =.008), hunger ( p =.02) and binge eating scores ( p =.02), but not cognitive restraint ( p =.37) compared to food secure individuals. They overate more kcal ( p =.001), %WMEN ( p =.003), fat ( p =.003) and carbohydrates ( p =.004) during the vending machine paradigm, continued to increase their hourly rate of kcal (group×time, β=37.7 cumulative kcal/hour, p <.0001) and ate more total kcal across the 72-hours (β=47.09 kcal/hour, p =.003). Conclusion: Food insecurity may amplify susceptibility to weight gain via overeating during times of unlimited food access.

Obesity is associated with reduced activation in the left dorsolateral prefrontal cortex (DLPFC), a region of the brain that plays a key role in the support of self-regulatory aspects of eating behavior and inhibitory control. Transcranial direct current stimulation (tDCS) is a noninvasive technique used to modulate brain activity. We tested whether repeated anodal tDCS targeted at the left DLPFC (compared with sham tDCS) has an immediate effect on eating behavior during ad libitum food intake, resulting in weight change, and whether it might influence longer-term food intake-related appetite ratings in individuals with obesity. In a randomized parallel-design study combining inpatient and outpatient assessments over 31 d, 23 individuals with obesity [12 men; mean ± SD body mass index (BMI; in kg/m): 39.3 ± 8.42] received 15 sessions of anodal (i.e., enhancing cortical activity) or sham tDCS aimed at the left DLPFC. Ad libitum food intake was assessed through the use of a vending machine paradigm and snack food taste tests (SFTTs). Appetite was evaluated with a visual analog scale (VAS). Body weight was measured. We examined the effect of short-term (i.e., 3 sessions) and long-term (i.e., 15 sessions) tDCS on these variables. Relative to sham tDCS, short-term anodal tDCS did not influence ad libitum intake of food from the vending machines. Accordingly, no effect on short-term or 4-wk weight change was observed. In the anodal tDCS group, compared with the sham group, VAS ratings for hunger and the urge to eat declined significantly more ( = 0.01 and = 0.05, respectively), and total energy intake during an SFTT was relatively lower in satiated individuals ( = 0.01), after long-term tDCS. Short-term anodal tDCS of the left DLPFC did not have an immediate effect on ad libitum food intake or thereby weight change, relative to sham tDCS. Hunger and snack food intake were reduced only after a longer period of anodal tDCS in individuals with obesity. This trial was registered at clinicaltrials.gov as NCT00739362.

Poorer response inhibition and depressive symptoms, but not glucose levels, predicted weight gain. Evaluating neurocognitive and mood deficits could improve current treatment strategies for weight loss. Clinical Trial Registration Numbers NCT00523627, NCT00342732, NCT01224704. clinicaltrials.gov.

Background: Higher energy expenditure (EE) is associated with greater food intake, possibly because the human body senses EE and modifies eating behaviors to regulate food intake and ultimately achieve energy balance. As eating behaviors are also influenced by social and cultural factors, any association between EE and eating behavior may differ between ethnicities and sexes. Objective: To assess relationships between EE and eating behavior constructs of the Three-Factor Eating Questionnaire (TFEQ). Subjects/Methods: 307 healthy adults (201M/106F, 160 Native Americans) completed the TFEQ and had measures of 24-h EE in a whole-room calorimeter during energy balance. Body composition was assessed by DXA. Results: On average, adjusted 24-h EE was lower (β=−229 kcal/day, CI: −309-−148, p <0.001) but cognitive restraint (Δ=+1.5; CI: 0.5–2.5, p= 0.003) and disinhibition (Δ=+2.1, CI: 1.3–2.8, p< 0.001) scores were higher in women compared to men. In Native Americans, adjusted 24-h EE (β=+94 kcal/day, CI: 48–139, p <0.001) and disinhibition scores (Δ=+1.0, CI: 0.1–2.0, p =0.003) were higher compared to other ethnicities. Higher 24-h EE associated with lower cognitive restraint in women (ρ=−0.20, p =0.04), but not men ( p =0.71; interaction term p =0.01) with no ethnic differences. Greater 24-h EE associated with higher disinhibition (ρ=0.20, p =0.001) and hunger cues (ρ=0.16, p =0.004) with no gender differences. These associations were primarily present in non-Native Americans (ρ=0.23, p =0.006 and ρ=0.25, p =0.003) but not observed in Native Americans (both p >0.40). Conclusions: Higher EE is associated with psychological constructs of eating behaviors that favors overeating including lower cognitive restraint, higher dietary disinhibition, and greater susceptibility to hungers cues, supporting the existence of energy-sensing mechanisms influencing human eating behavior. These associations were observed in ethnicities other than Native Americans, possibly explaining the contradictory relationships reported between EE and weight change in different ethnic groups. We propose that increased EE may alter eating behaviors, potentially leading to uncontrolled overeating and weight gain.

ObjectiveTo determine how macronutrients accompanying high-EnDen foods affect energy intake and weight gain.Methods214 subjects(130 males, BMI:32 ± 7 kg/m2) ate ad libitum for 3-days. Food intake was expressed as mean daily intake(kcal) and percentage of weight-maintaining energy needs(%WMEN). EnDen was expressed as the ratio of intake(kcal) to food weight(g). Food choices were expressed as absolute and percent intake(kcal), categorized as high(HF; ≥45% kcal) or low in fat(LF; <20% kcal) and further categorized as high in complex-carbohydrates(HCC; ≥30% kcal), simple-sugars(HSS; ≥30% kcal), or protein(HP; ≥13% kcal). 99 subjects had follow-up weights(65m, range:6months-11yrs).ResultsEnDen was associated with BMI(r= .28, p<.0001), %body fat(r=.18, p=.007), and percent intake from HF/HP(r=.34, p <.0001), HF/HSS(r=.31, p< .0001), LF/HP (r=−.37, p<.0001) and LF/HSS(r=−.68, p< .0001). %WMEN was associated with EnDen(r=.16, p=.01), HF/HSS (r=.33, p<.0001) and LF/HP intake(r=−.25, p=.0002). In a multivariate model, only HF/HSS intake remained a significant predictor of %WMEN(β=1.4% per 1% change, p<.0001). Percent intake from HF/HSS(r=.23, p=.02), not EnDen(p=.54), was associated with weight gain, even after adjusting for follow-up time(yrs) and covariates.ConclusionsRelatively greater consumption of HF/HSS foods independently predicted overeating and weight gain. Nutrient compositions of high-EnDen foods may be important for weight management.

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.

Purpose-Glucagon-like peptide 1 (GLP-1) is an incretin hormone that appears to play a major role in the control of food intake. The aim of this investigation was to evaluate and quantify the association of circulating GLP-1 concentration with ad libitum total calorie and macronutrient intake.Methods-One-hundred fifteen individuals (72 men) aged 35 ± 10 years were admitted for an inpatient study investigating the determinants of energy intake. Ad libitum food intake was assessed during 3 days using a reproducible vending machine paradigm. Fasting plasma GLP-1 concentrations were measured on the morning of the first day and on the morning of the fourth day after ad libitum feeding.Results-Plasma GLP-1 concentrations increased by 14% after 3 days of ad libitum food intake. Individuals overate on average 139 ± 45% of weight-maintaining energy needs. Fasting plasma GLP-1 on day 1 was negatively associated with carbohydrate intake (r=−0.2, p=0.03) and with daily energy intake from low fat-high simple sugar (r=−0.22, p=0.016). Conclusion-Higher plasma GLP-1 concentrations prior to ad libitum food intake were associated with lower carbohydrate intake and lower simple sugar ingestion, indicating a possible role of the GLP-1 in the reward pathway regulating simple sugar intake.