The secret to longevity in Japan is likely the healthy Japanese diet, which is low in foods containing heart-damaging trans fats and sodium and high in fresh vegetables and fatty fish such as salmon, fresh tuna, mackerel, sardines, and herring that are a great source of heart-healthy omega-3 fatty acids.

In addition, Japanese people have the lowest obesity rate in the developed world — 3%–versus 11% for the French and 32% for Americans, according to the International Obesity Task Force. This is not a genetic trait, say dietary experts, because when Japanese people adopt a Western-style diet heavy in red meat, fast foods, and fried foods, they put on weight quickly.

Still, studies show that the average Japanese adult eats about 25% fewer calories per day than the average American, which could partly explain their lengthy lifespan.