Women who add more fat to their bodies as they approach menopause will have a harder time with hot flashes and night sweats.
Fat was perceived to protect women against vasomotor symptoms (hot flashes and night sweats) because it contains hormones that can be converted into oestrogen. However, recent research has shown that women with higher body mass index and more body fat actually suffer more hot flashes.
Gains in body fat are common over the course of midlife and the menopausal transition. To investigate whether these gains might be related to menopausal symptoms, researchers studied 1,659 American women 47 to 59 years old for four years. Every year, they checked women's hormone levels, percentage of body fat, and frequency of hot flashes and night sweats.
During follow-up, 53 percent of the women showed an increase in body fat - on average, about a half percent. In 24 percent of the women, body fat percentage shrank, while it remained stable for the remaining 23 percent.
The women who gained fat were 1.2 times more likely to report having hot flashes. The relationship remained after they accounted for the women's hormone levels, but was not significant for night sweats, which could be because it is harder to keep track of night sweats, largely because they happen while one is sleeping.
The researchers noted that fat might worsen hot flashes because it acts as an insulator and makes it harder for the body to get rid of heat. Hot flashes and night sweats may happen because it's tougher for a woman's internal thermostat to maintain a steady core body temperature during menopausal hormone shifts.
The researchers recommended women to avoid gaining weight by maintaining a healthy diet and being active to prevent gaining body fat as well as symptoms of hot flashes.