Effects of dietary factors on energy regulation: consideration of multiple- versus single-dietary-factor models.

While short-term studies demonstrate consistent effects of dietary protein, fiber, glycemic index and energy density on energy intake, long-term effectiveness trials typically indicate small or non-significant effects of these dietary factors on long-term weight change. In consequence, most lifestyle interventions for weight control typically focus on a single dietary factor, such as low energy density, to achieve reductions in energy intake. This paper proposes a multiple-dietary-factor model for the effects of dietary factors on energy intake and the regulation of energy balance that assumes additive effects of different dietary factors. The model is consistent with emerging evidence from recent studies examining pairs of dietary factors. Randomized clinical trials are now needed to determine whether multiple-dietary-factor prescriptions combined with standard behavior modification techniques lead to improved sustainability of weight loss in lifestyle interventions compared to conventional single-dietary-factor prescriptions.