The phenomenon known as natsubate (summer fatigue) in Japanese is not to be taken lightly, especially when the heat and humidity is as brutal as it's been this summer. Natsubate, the fatigue and lethargy you feel during the summer months, can seriously affect your energy levels and even make you feel sick.
The usual advice about drinking plenty of liquids and to protect yourself from the sun as much as possible both apply. But there are also things you can eat that may help combat the effects of natsubate, too.
Thiamine (vitamin B1) is said to be especially effective in combating natsubate, and one food that's rich in thiamine is pork. Severe thiamine deficiency can cause an illness called beriberi, which was so prevalent in the Edo Period (1603-1868) that it was commonly called the "Edo disease." This was largely due to a meatless diet, coupled with the firm belief that plain white rice made for a complete meal.