Men in their 30s and 40s are increasingly becoming overweight and are also increasingly likely to have hyperlipemia, according to a survey released Wednesday by the Ministry of Health, Labor and Welfare.

The ministry's fifth basic survey on circulatory diseases showed the present unhealthy state of Japanese men who are in their prime, revealing, among other things, that those in their 30s are about twice as overweight as their female counterparts.

The survey, carried out every 10 years, was conducted last November and covered 8,369 male and female respondents across Japan aged over 30.

In contrast, the trend of slimming among women in their 30s and 40s has been continuing for 10 to 20 years, due to the influence of dieting and other factors, according to the ministry. It noted that there is also a rise in problems of women dieting too much.

Incidence of overweight men was 28.2 percent, while that of overweight women was 23.6 percent. The survey said that males of all ages tend toward being overweight compared to 10 to 20 years ago, based on the average of the body mass index, a method of discerning whether a person is overweight.

As for hyperlipemia, the survey noted that in general there has been a decrease, except for men in their 30s and 40s. Hyperlipemia is a blood disorder characterized by the presence of excess lipids, or fatty compounds, in the blood. It causes arterial sclerosis.

Also, in terms of blood pressure, men in their 30s are about three times more unhealthy than their female counterparts, while men in their 40s are twice as unhealthy, the survey said.

As hyperlipemia and being overweight are risk factors linked to heart disease and stroke — leading causes of death in Japan — the survey suggests the importance of improving such lifestyle habits as diet.