The effects of short-term overfeeding on energy expenditure and nutrient oxidation in obesity-prone and obesity-resistant individuals

Abstract

Objective The roles that energy expenditure (EE) and nutrient oxidation play in a predisposition for weight gain in humans remains unclear. Subjects We measured EE and respiratory exchange ratio (RER) in non-obese obesity prone (OP; n=22) and obesity resistant (OR; n=30) men and women following a eucaloric diet and after 3 days of overfeeding (1.4x basal energy). Results Twenty four hour EE, adjusted for fat free mass and sex, measured while consuming a eucaloric diet was not different between OP and OR subjects (2367 ± 80 vs. 2285 ± 98 kcals; p=0.53). Following overfeeding, EE increased in both OP and OR (OP: 2506 ± 63.7, p<0.01; OR: 2386 ± 99 kcals, p<0.05). Overfeeding resulted in an increase in 24h RER (OP: 0.857 ± 0.01 to 0.893 ± 0.01, p=0.01; OR: 0.852 ± 0.01 to 0.886 ± 0.01, p=0.005), with no difference between groups in either the eucaloric or overfeeding conditions (p>0.05). Nighttime RER (~10pm-6:30am) did not change with overfeeding in OR (0.823 ± 0.02 vs. 0.837 ± 0.01, p=0.29), but increased significantly in OP subjects (0.798 ± 0.15 to 0.839 ± 0.15, p<0.05), suggesting that fat oxidation during the night was down-regulated to a greater extent in OP subjects following a brief period of overfeeding, as compared to OR subjects who appeared to maintain their usual rate of fat oxidation. Protein oxidation increased significantly in both OP (p<0.001) and OR (p<0.01) with overfeeding, with no differences between OP and OR. Conclusion These results support the idea that overfeeding a mixed diet results in increases in EE and RER, but these increases in EE and RER are likely not responsible for obesity resistance. Adaptive responses to overfeeding that occur during the night may play a role in opposing weight gain.

Disproportionately increased 24-h energy expenditure and fat oxidation in young men with low birth weight during a high-fat overfeeding challenge

“…The more pronounced differences in fat versus glucose oxidation as observed during nighttime in the LBW versus NBW subjects are in agreement with our results obtained in the same subjects during a weight-maintaining control diet [4] and could be due to differential expressions of clock genes regulating the circadian rhythm and/or diurnal hormones [28]. Furthermore, the observed diurnal metabolic differences could potentially be associated with a reduced ability to store fat in the subcutaneous adipose tissue as discussed [4].…”

Propensity to Obesity Impacts the Neuronal Response to Energy Imbalance

“…As we have previously described, subjects were recruited to have a propensity to be resistant to weight gain and obesity (OR) or to be prone to weight gain and obesity (OP) (Schmidt et al, 2012, 2013; Smucny et al, 2012; Cornier et al, 2013; Thomas et al, 2013, 2014). Subjects were 25–40 years of age and were free of significant medical and psychiatric disease, including eating disorders as assessed by screening medical history, physical examination, biochemical testing, and questionnaires [eating attitudes test (Garner et al, 1982) and the Center for Epidemiologic Studies Depression Scale (Radloff, 1977)].…”

Incorporation of therapeutically modified bacteria into gut microbiota inhibits obesity

“…A reduced RQ when switching to high-fat diets predicts lower long-term weight gain and body fat in humans (61). Conversely, individuals prone to obesity have blunted lowering of their RQ in response to deliberate short-term overeating of a balanced diet (62). Therefore, the ability of pNAPE-EcN treatment to increase expression of fatty acid oxidation genes and resting energy expenditure may be important mechanisms contributing to its long-term efficacy in lowering adiposity.…”