Several public health researchers have developed indexes for assessing the quality of people’s diets. Other studies have shown that not just what people eat, but how they eat, strongly affects body weight and health. However, no tool exists that can combine these insights on how people eat with analysis of the overall quality of their diets. We thus sought to analyze the relationship between mealtime habits, including complex patterns of these behaviors on diet and weight control. The aim of this these is to construct and validate an index for assessing the quality of mealtime habits, as evaluate their influence on weight change, that epidemiological researchers and public health workers can use to assess and redress the effects of specific sets of eating behaviors on diet and overall health.