Energy Expenditure Responses to Fasting and Overfeeding Identify Phenotypes Associated With Weight Change

Abstract

Because it is unknown whether 24-h energy expenditure (EE) responses to dietary extremes will identify phenotypes associated with weight regulation, the aim of this study was to determine whether such responses to fasting or overfeeding are associated with future weight change. The 24-h EE during energy balance, fasting, and four different overfeeding diets with 200% energy requirements was measured in a metabolic chamber in 37 subjects with normal glucose regulation while they resided on our clinical research unit. Diets were given for 24 h each and included the following: 1) low protein (3%), 2) standard (50% carbohydrate, 20% protein), 3) high fat (60%), and 4) high carbohydrate (75%). Participants returned for follow-up 6 months after the initial measures. The decrease in 24-h EE during fasting and the increase with overfeeding were correlated. A larger reduction in EE during fasting, a smaller EE response to low-protein overfeeding, and a larger response to high-carbohydrate overfeeding all correlated with weight gain. The association of the fasting EE response with weight change was not independent from that of low protein in a multivariate model. We identified the following two independent propensities associated with weight gain: a predilection for conserving energy during caloric and protein deprivation and a profligate response to large amounts of carbohydrates.

Brown and Beige Adipose Tissues in Health and Disease

“…Mounting evidence supports the notion that BAT- and beige fat-mediated thermogenesis contributes to energy expenditure and protects against obesity. In line with this notion, a variety of metabolic hormones, metabolites, and nutrients are able to stimulate brown and/or beige adipogenesis (276); BAT and beige fat in turn mediate, at least in part, diet-induced thermogenesis, thus counteracting weight gain (85, 262, 270, 340). Using either pharmacological or genetic approaches, activation of BAT and beige fat thermogenesis considerably induces weight loss in rodents (275, 319).…”

“…Food intake is well known to increase nonshivering thermogenesis in rodents and humans (262, 270). Ingestion of energy dense food (e.g.…”

Hyperinsulinemia: a Cause of Obesity?

“…Inadequacy of our conceptual understanding of obesity is documented by randomized clinical trial data showing the following:Overeating causes short-term weight gain but is often not sustained [1, 2••].Dieting leads to weight loss but is rarely sustained [1, 2••].Inactivity does not cause obesity.Exercise improves health but does not cure obesity [3••]. …”

Changes in Energy Expenditure with Weight Gain and Weight Loss in Humans

“…In a given individual, both mechanisms add to efficient energy use to conserve body energy providing a so-called thrifty phenotype [32, 33]. Vice versa , a low AT in response to negative energy balance together with a high AT during positive energy balance favours weight loss during caloric restriction and limits weight gain with overfeeding altogether characterising a so-called spendthrift phenotype [32, 33]. Over long-term, metabolic phenotypes characterised by AT are correlated to subsequent weight changes.…”