Dietary factors affect food reward and motivation to eat.

The propensity to indulge in unhealthy eating and overconsumption of palatable food is a crucial determinant in the rising prevalence of obesity in today's society. The tendency to consume palatable foods in quantities that exceed energy requirements has been linked to an addiction-like process. Although the existence of 'food addiction' has not been conclusively proven, evidence points to alterations in the brain reward circuitry induced by overconsumption of palatable foods that are similar to those seen in drug addiction. The diet-induced obesity paradigm is a common procedure to replicate features of human obesity in rodents. Here we review data on the effect of various obesogenic diets (high-fat, Ensure™, cafeteria type, sucrose) on the extent of leptin resistance, hypothalamic-neuropeptidergic adaptations and changes in feeding behavior. We also discuss to what extent such diets and properties such as macronutrient composition, physical structure, sensory stimuli, and post-ingestive effects influence the brain-reward pathways. Understanding the interaction between individual components of diets, feeding patterns, and brain reward pathways could facilitate the design of diets that limit overconsumption and prevent weight gain.