Energy intake and obesity: Ingestive frequency outweighs portion size

• Ingestive frequency and portion sizes are not balancing to sustain stable body weight
• Different mechanisms drive ingestive frequency and portion size
• Physiological and behavioral factors influence ingestive frequency and portion size
• Ingestive frequency may contribute more to positive energy balance than portion size

Energy intake is a function of the quantity of energy consumed per ingestive event and the number of these events. The marked increase of energy intake and body weight over the past 35 years indicates that there has been poor precision in the reciprocity of these two facets of intake. With recent study of the associations between gut “satiation” peptides and energy intake, there has been an emphasis on the contribution of portion size to positive energy balance. However, this orientation may not appropriately weight the contribution of ingestive frequency. Gut peptides are not purely satiation factors and metabolic and environmental cues may more strongly guide the onset and number of ingestive events. Evidence is presented that while both portion size and ingestive frequency have increased in the population, the latter may be more problematic for weight gain. The magnitude and time course of increments in ingestive frequency map better onto energy intake and BMI trends than changes of portion size. This may occur, in part, because dietary compensation and thermogenic effects are weaker for increases in ingestive frequency than portion size. Though not to the exclusion of consideration of portion size effects, improved weight management may be achieved with greater attention to the drivers of eating and drinking frequency.