Short-term intake of a Japanese-style healthy lunch menu contributes to prevention and/or improvement in metabolic syndrome among middle-aged men: a non-randomized controlled trial

BACKGROUND: Metabolic syndrome is now widely appreciated as a cluster of metabolic abnormalities such as visceral obesity, hypertension, hyperglycemia and dyslipidemia. To date, incidence of metabolic syndrome is continuously increasing worldwide. In addition, low vegetable consumption has recently become a serious issue in Japan. Furthermore, Japan is facing a shortfall in places offering food that can help prevent metabolic syndrome in the first place. Our study is designed to influence these developments. We conducted a non-randomized controlled trial by offering a Japanese-style healthy lunch menu to middle-aged men in a workplace cafeteria. This menu was designed to prevent and reduce metabolic syndrome. METHODS: This intervention study took the form of a non-randomized controlled trial. Participants chose the control or intervention group. The control group consumed their habitual lunches without restriction and only nutrient contents were assessed. The intervention group received a Japanese-style healthy lunch at a workplace cafeteria for 3 months. The participants worked in offices at a city hall and mostly had low levels of physical activity. Data of 35 males (control group: 7 males, intervention group: 28 males, mean age: 47.2 ± 7.9 years) were collected and analyzed. RESULTS: We obtained an effective outcome by demonstrating that ongoing intake of a Japanese-style healthy lunch decreased blood pressure and serum lipids and increased plasma ghrelin levels. The results grew more pronounced as intake of Japanese-style healthy lunches increased in frequency. CONCLUSIONS: This study presents new empirical data as a result of an original intervention program undertaken in Japan. A Japanese-style healthy lunch menu containing many vegetables consumed can help prevent and/or improve metabolic syndrome.