Healthy Diets Are Associated with Weight Control in Middle-Aged Japanese

Background/Objectives: In Japan, well-balanced meals composed of staple grains, protein-rich main dishes, and vegetable sides are recommended. However, issues such as infrequent breakfast consumption and poor vegetable intake persist. Obesity and non-communicable disease (NCD) rates from age 40 have also begun rising. Therefore, we investigated the structural associations between healthy diets and weight control for NCD prevention, including the potential associations with rice consumption and eating out/home meal replacement use in middle-aged Japanese individuals. Methods: This study was a cross-sectional survey based on data from 577 respondents to the 2016 Hyogo Diet Survey, Hyogo Prefecture, Japan, aged 40-59 years. A healthy diet was defined as including at least two well-balanced meals daily, eating breakfast regularly, and eating five or more vegetable dishes daily. A hypothetical model included factors associated with healthy diets and maintaining a healthy weight (energy, salt, fat, and sugar intake; using nutritional fact labels; and regular exercise), and the frequencies of rice consumption and eating out/home-meal replacement. A simultaneous multi-population analysis by sex was performed. Results: Simultaneous multi-population analysis showed acceptable goodness-of-fit. Maintaining appropriate weight and eating rice were positively associated with healthy diet scores in both sexes. However, for men, using home meal replacements was negatively associated. Conclusions: Among middle-aged Japanese in Hyogo Prefecture, weight control for NCD prevention and rice consumption were linked to healthy diets. In men, using home meal replacements was associated with worse diet quality.