Compared with placebo, exenatide decreased early ad libitum energy intake but did not change 24 h-EE. However, the reduction was more modest in relative versus absolute terms (i.e. below that needed for WMEN). Thus, although rate of weight change was greater in the exenatide treated subjects at 5 weeks, the absolute difference in weight was not significant. These findings indicate that although exenatide reduces food intake, it may be more beneficial in blunting overeating and thus may serve to more prevent weight regain following initial weight loss.

Independent from dietary macronutrient proportions, there is a strong individual contribution to fuel preference that remains consistent across diets. Higher urinary epinephrine levels may reflect the importance of epinephrine in maintaining EE during fasting.

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.

OBJECTIVE Differences in executive function have been associated with eating behaviors. Our aim was to determine whether measures of executive function predicted ad libitum food intake in subjects seeking weight loss. METHODS This cross-sectional study involved 78 obese, otherwise healthy, individuals (40 female /38 male; age 36±10y; BMI 37.8±7.2 kg/m2) enrolled in weight loss studies, but prior to any intervention. Participants completed the Iowa Gambling Task to evaluate decision making, the Stroop Word Color Task to assess attention, the Wisconsin Card Sorting Task (WCST) to measure perseverative errors, and the Three Factor Eating Questionnaire (TFEQ) to measure disinhibition and cognitive restraint. Ad libitum energy intake over 3-days was then collected using a validated vending paradigm. RESULTS Only results from the WCST and the TFEQ correlated with mean daily energy intake. When expressed as a percentage of an individual's calculated weight maintaining energy needs (%WMEN; [mean daily energy consumed/WMEN]*100), intake correlated positively with number of perseverative errors (r = 0.24, p = 0.03) and negatively with cognitive restraint (r2 = −0.51, p<0.0001). In a regression model of %WMEN (r2 = 0.59, p<0.0001) including age, sex, race, disinhibition, restraint, and perseverative error T-score, an interaction between perseveration and restraint was observed (p = 0.05). Greater numbers of perseverative errors intensified the effect of restraint such that subjects with both high restraint and high perseveration, per manual-defined cut-offs, ate the least (median (IQR) = 70 (62, 94) % WMEN), while those with low restraint and high perseveration ate the most (130 (102, 153) %WMEN). Subjects with low perseveration and high versus low restraint ate a median of 84 (70, 86) and 112 (98, 133) %WMEN, respectively. CONCLUSION In obese subjects seeking weight loss, the effects of perseveration on food intake are conditional on the level of dietary restraint, and may contribute to increased intake exhibited by some subjects when self-control is undermined.