Objective Reduced dorsolateral prefrontal cortex (dlPFC) activity and inhibitory control may contribute to obesity. The study objective was to assess effects of repeated transcranial direct current stimulation (tDCS) on food Go/No‐Go (GNG), food Stroop performance, and snack food intake. Methods Twenty‐nine individuals with obesity (12 male; mean [SD], age 42 [11] years; BMI 39 [8]) participated in a combined inpatient/outpatient randomized parallel‐design trial and received 15 sessions of anodal or sham tDCS to the left dlPFC. Food‐related inhibitory control (GNG), attentional bias (Stroop), and snack food intake were assessed at baseline, completion of inpatient sessions (day 7), and follow‐up (day 31). Results GNG performance improved in the anodal group by day 31, compared with sham (p = 0.01), but Stroop scores did not differ by intervention. Greater snack food intake was associated with lower GNG scores (p = 0.01), driven by the sham group (p < 0.001) and higher food and palatable bias scores on the Stroop (all p = 0.02) across both groups. Changes on tasks were not associated with changes in intake. Conclusions Anodal tDCS to the left dlPFC improved performance on a food‐related inhibitory control task, providing evidence of potential for therapeutic benefit of neuromodulation in areas controlling executive function. Results showed that tDCS to the dlPFC reduced snack food intake and hunger; however, underlying neurocognitive mechanisms remain uncertain.

Objective Fidgeting, a type of spontaneous physical activity (SPA), has substantial thermogenic potential. This research aims to examine secular trends in SPA and energy expenditure (EE) inside a respiratory chamber. Methods From 1985 to 2005, healthy adults (n = 678; mean age: 28.8 years; men: 60%; 522 Indigenous American, 129 White, and 27 Black) had a 24‐hour stay in the respiratory chamber equipped with radar sensors. Body composition, glucose tolerance, fasting insulin, insulin action (hyperinsulinemic‐euglycemic clamp), and insulin secretion (intravenous glucose tolerance test) were measured as covariates. Results SPA, adjusted for age, sex, race, and body composition, declined (r = −0.30, p < 0.0001), with a concomitant rise in the energy cost of SPA (r = 0.30, p < 0.0001). The 24‐hour EE adjusted for covariates increased (r = 0.31, p < 0.0001), which was reflected in increases in EE during sleep (r = 0.18, p < 0.0001) and during the awake, fed condition (r = 0.28, p < 0.0001). The secular trends in SPA or 24‐hour EE were unchanged with adjustment for measures related to glucose metabolism. Conclusions Secular trend analyses showed a decline in fidgeting. However, this decline in SPA was partially counterbalanced by an increase in energy cost of this activity and a rise in EE. Nevertheless, our results support public health efforts to promote small but sustained changes in these behaviors.