Low energy intake plus low energy expenditure (low energy flux), not energy surfeit, predicts future body fat gain

The energy surfeit theory, which is commonly apply in weight management, emphasized to attain negative energy balance (Energy expenditure > Energy Intake) for weight reduction.

However, this weight reduction is not always sustainable (most people who used a reduced-calorie weight loss strategy regain the lost weight).
Maintaining high energy flux (high energy intake and expenditure) may induces metabolic changes that are more protective against weight gain than a prolonged negative energy balance from dietary restrictions.

This study tested whether energy balance or energy flux predict future weight gain, in a group of healthy-weight adolescents and slightly heavier young adults, by using objective method to estimate energy intake and expenditure.
- Energy balance = Total Energy Intake (TEI) - Total Energy Expenditure (TEE)
- Energy flux = TEI + TEE

It was found that Energy Balance did NOT predict weight gain, but Low Energy Flux predicted future body fat gain (moderate relationship). What is even more surprising is that, the low energy flux group that showed increases in body fat was in a negative energy balance at baseline, whereas the high energy flux group that showed decreases in body fat was in a positive energy balance at baseline.

The results are consistent with the thesis that homeostatic regulation of body weight is more effective when energy balance is sustained at high levels of energy intake and energy expenditure, supporting the premise that energy-restrictive diets, particularly when coupled with low exercise, may not be optimal for weight loss.

This implies that regular physical activity may be key for effective long-term weight management, extending previous evidence that exercise is the best predictor of successful weight loss maintenance. Low-calorie diets theoretically reduce volitional physical activity and nonexercise-associated thermogenesis, which promote weight regain because they foster energy conservation.

What can we improve in our weight management strategy based on this (objective) finding?

Hume, Yokum, and Stice. Am J Clin Nutr 2016. doi: 10.3945/ajcn.115.127753.