Changes in brain activity after weight loss

The importance of the regulatory role of the brain in directing glucose homeostasis, energy homeostasis, eating behaviour, weight control and obesity is increasingly recognized. Brain activity in (sub)cortical neuronal networks involved in homeostatic control and hedonic responses is generally increased in persons with obesity. Currently, it is not known if these functional changes can be affected by dieting. The aim of the current study was to investigate whether prolonged fasting and/or weight loss influences neuronal brain activity in obese persons.

Fourteen participants with obesity were included (two male participants and 12 female participants, body mass index 35.2 ± 1.2 kg m^-2). Whole-brain resting-state functional magnetic resonance imaging was performed after an overnight fast, after a prolonged 48-h fast and after an 8-week weight loss intervention.

An 8-week weight loss intervention decreased BOLD signal in areas of the brain involved in salience, sensory motor and executive control. BOLD signal in these areas correlated with leptin levels and body mass index.

Weight loss decreased activity in brain areas involved in feeding behaviour and reward processing. These results indicate that these obesity-associated alterations in neuronal activity are related to excessive body weight and might change after weight loss.