Research

Energy balance

Obese subjects exhibit a significantly reduced thermic effect of glucose (approx. 5.2% increase in metabolic rate) compared to lean controls (approx. 13.0% increase) following a 50g glucose load, suggesting inefficient dietary-induced thermogenesis contributes to low energy expenditure in obesity.

This research suggests that obese individuals may burn fewer calories from food (specifically glucose) than lean individuals due to a blunted thermic effect. This isn't about willpower; it's a physiological difference in how energy is expended. Understanding this metabolic inefficiency can help shift the focus from just 'eating less' to strategies that might address metabolic rate and energy expenditure.

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In the control group, this increase was 13.0 % of the initial (fasting) value, whereas in the obese group it was only 5.2 %, i.e. about half the thermic effect found in the control group. This difference in metabolic rate stimulation was highly significant
P Pittet et al. · British Journal Of Nutrition · 1976

Why this rating

Direct calorimetry is the gold standard for measuring heat production; the study uses this rigorous method, though the sample size is small (n=21).

Source

Thermic effect of glucose in obese subjects studied by direct and indirect calorimetry

P Pittet et al. · British Journal Of Nutrition · 1976

DOI 10.1079/bjn19760033

crossover · n=21Cited 172×
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DOI resolved against Crossref · corpus check 2026-06-10

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