Estrogen deficiency after menopause is thought to impair the ability to use fat as an energy source. A study published in Nutrition, Metabolism and Cardiovascular Diseases and conducted at the Faculty of Sports and Health Sciences at the University of Jyväskylä has shown that menopause and blood estrogen levels do not clearly determine the rate of fat utilization at rest or during exercise in middle-aged women. Higher fat utilization does not indicate better glucose tolerance. Estrogen is seen as a hormone that promotes fat burning. After menopause, estrogen levels decrease. The resulting estrogen deficiency is thought to reduce the female body’s ability to use fat as an energy source, potentially leading to weight gain and metabolic impairment. Estrogen levels can be restored with hormone replacement therapy. A study conducted at the University of Jyväskylä has shown that the effect of menopause on fat utilization is probably negligible compared to dietary habits and levels of physical activity. When the rate of fat absorption is measured at rest after an overnight fast, its primary determinant is energy balance. Women whose energy intake was lower compared to energy expenditure had a higher use of fat as an energy reserve. Higher fat utilization is also characterized by higher levels of fatty acids and ketones in the blood. However, fat use in postmenopausal women did not differ from women who had not yet reached menopause or were using hormone replacement therapy. Women burn fat even after menopause if their energy intake is less than their expenditure, the scientists explain. The highest rate of fat utilization was measured during a bicycle test. The highest indicators were achieved by women with the highest levels of physical activity. Here again, postmenopausal women’s outcomes were no different from women who had not reached menopause or who used hormone replacement therapy. To improve the ability to burn fat during exercise, it is important to improve fitness with endurance training, the researchers explained. Previous research has shown that the ability to burn fat during exercise improves with exercise even after menopause. The study also investigated whether higher fat intake indicated better glucose tolerance. In women whose fat was used at higher levels at rest, blood sugar and insulin levels rose more during a subsequent glucose tolerance test. Higher fat utilization during exercise does not indicate better glucose tolerance. When more resting fat is used as an energy source,consuming carbohydrates can raise blood sugar levels. The body momentarily adjusts to using more fat. A high-fat diet does increase the total amount of fat used for energy production. However, this is due to increased fat intake and does not mean that fat expenditure will suddenly increase sharply. When energy intake is less than energy expenditure, weight is similarly reduced, regardless of dietary macronutrient distribution. References: https://dx.doi.org/10.1016/j.numecd.2022.06.001