Metabolic adaptation is not observed after 8 weeks of overfeeding but energy expenditure variability is associated with weight recovery.

Background: A metabolic adaptation, defined as an increase in energy expenditure (EE) beyond what is expected with weight gain during overfeeding (OF), has been reported but also refuted. Much of the inconsistency stems from the difficulty in conducting large, well-controlled OF studies in humans.

Objectives: The primary aim of this study was to determine whether a metabolic adaptation to OF exists and if so, attenuates weight gain.

Impact of prolonged overfeeding on skeletal muscle mitochondria in healthy individuals.

Aims/hypotheses: Reduced mitochondrial capacity in skeletal muscle has been observed in obesity and type 2 diabetes. In humans, the aetiology of this abnormality is not well understood but the possibility that it is secondary to the stress of nutrient overload has been suggested. To test this hypothesis, we examined whether sustained overfeeding decreases skeletal muscle mitochondrial content or impairs function.

Intramyocellular Lipid Droplet Size Rather Than Total Lipid Content is Related to Insulin Sensitivity After 8 Weeks of Overfeeding.

Objective: Intramyocellular lipid (IMCL) is inversely related to insulin sensitivity in sedentary populations, yet no prospective studies in humans have examined IMCL accumulation with overfeeding.

Methods: Twenty-nine males were overfed a high-fat diet (140% caloric intake, 44% from fat) for 8 weeks. Measures of IMCL, whole-body fat oxidation from a 24-hour metabolic chamber, muscle protein extracts, and muscle ceramide measures were obtained before and after the intervention.

Eight weeks of overfeeding alters substrate partitioning without affecting metabolic flexibility in men.

Background/objective: Impairments in metabolic flexibility (MF) and substrate handling are associated with metabolic syndrome. However, it is unknown whether metabolic inflexibility causes insulin resistance. We therefore measured MF and substrate handling before and after 8 weeks of overfeeding in initially healthy adults as a model of the early stages of insulin resistance.

Lifestyle modification intervention improves glycemic control in Mongolian adults who are overweight or obese with newly diagnosed type 2 diabetes.

Objective: To evaluate the effectiveness of a weight loss intervention in Mongolian adults with newly diagnosed type 2 diabetes mellitus and with BMIs ≥ 25.0 kg/m.

Methods: Eighty participants (33 men/47 women) aged 32-56 years old received education sessions to improve nutritional habits and increase physical activity.