更年期和体重增加

jacky

Menopause & Weight Gain Monday, October 06, 2008
by doFIT experts

Menopause is defined as the end of menstruation. The postmenopausal period is associated with symptoms such as hot flashes, changes in libido and weight gain. In America, the typical woman reaches menopause at just over 51 years of age.  According to the Centers for Disease Control and Prevention (CDC), in 2005, the average American woman reaching age 50 could expect to live another 30 years.  This means that if a woman gains weight at menopause, she will be dealing with it for three decades. Does reaching menopause mean you’re destined to gain excess weight? Is losing weight after menopause harder than it would be before menopause? The purpose of this article is to explore these questions and discuss the key times in a woman’s life when weight gain seems inevitable.

The typical American woman will experience numerous changes in body shape during her life, specifically just after high school, childbearing and menopause.  The culprit for young women is often a significant decrease in activity after high school leading to the infamous “Freshman 15”. ,  Pregnancy is an obvious time for weight gain, but most women reach their prepregnancy weight within six months of giving birth - at least after their first child.1  The women in both scenarios can change their weight or body fat by eating less and moving more. See "Weight Control 101" for a complete discussion.

The common belief with menopause is that the decrease in female hormones somehow leads to a slower metabolism or increased body fat. Several studies have evaluated whether there is a specific change around menopause that leads to weight gain, or at least makes it easier. These studies have shown that the biggest change affecting body weight around menopause is a reduction in activity. This is a common theme at various stages of a woman’s life. That is, a relatively steady or slight increase in calorie intake with decreasing activity over time. One strong predictor for obesity in a person’s life is age. Since the average woman gains about a pound yearly, it is much more likely that a middle-aged woman will be obese compared to a 20 year-old. Also, a woman with extra weight at adolescence is more likely to gain extra weight at other times such as her freshman year of college.

Some of the stronger studies on menopause looked at women of the same age who either still had periods or were in menopause. When pre- and postmenopausal women are matched for age, menopausal women have

• No difference in weight gain. Both pre and postmenopausal women gain weight. The difference is where the fat is stored. (7)
• No difference in loss of lean mass compared to premenopausal women. Both lost muscle tissue with time.
• An increase in central adiposity - more fat stored around the waist as opposed to the thighs or arms.
• No change in body composition. It seems the biggest effect of decreased estrogen is where fat is stored, not that more fat is stored.
• A possible small decrease in resting metabolic rate (RMR) from decreased estrogen, but not enough of a difference that menopausal women gain more weight. (7)
  

Hormone replacement therapy (HRT)

Some women take medication to replace the hormones lost from menopause. One question often asked about HRT is whether it causes weight gain. A three-year study found that there was no increase in body weight among HRT users compared to placebo regardless if they used estrogen or estrogen and progesterone combined.9 Women should discuss HRT with a physician who will assess any risk of hormone-dependent cancers.

In summary, menopause only means women will no longer have periods. It does not mean the body slows down to the point a woman is destined to gain weight. Postmenopausal women can lose weight just like premenopausal women. When postmenopausal women lose weight, they can lose both subcutaneous (under the skin) and visceral (around the organs) fat as easily as premenopausal women. This means postmenopausal women can reverse any weight gain.   In addition, weight loss among postmenopausal women is accompanied by the same improvements in cholesterol and reduced insulin resistance. This results in a lower risk of heart disease and diabetes.  Increasing activity can help prevent weight gain and improve health during this time.




References

• Beckman C, Ling F, Smith R, Barzansky B, Herbert W, Laube D. Obstetrics and Gynecology. Lippincott Williams and Wilkins. Philadelphia PA: 2006; 810p. pp. 128, 375.
• Kung HC, Hoyert DL, Xu J, Murphy SL. Life expectancy at selected ages by race and sex: United States, 2005 in: Deaths Final Data for 2005. National Vitals Statistics Reports 56(10)  Accessed at http://www.cdc.gov/nchs/data/nvsr/nvsr56/nvsr56_10.pdf September 2008.
• Jung ME, Bray SR, Martin Ginis KA. Behavior change and the freshman 15: tracking physical activity and dietary patterns in 1st-year university women. J Am Coll Health. 2008 Mar-Apr;56(5):523-30.
• Holm-Denoma JM, Joiner TE, Vohs KD, Heatherton TF. The "freshman fifteen" (the "freshman five" actually): predictors and possible explanations. Health Psychol. 2008 Jan;27(1 Suppl):S3-9.
• Mihalopoulos NL, Auinger P, Klein JD. The Freshman 15: is it real? J Am Coll Health. 2008 Mar-Apr;56(5):531-3.
• Simkin-Silverman LR, Wing R. WEIGHT GAIN DURING MENOPAUSE: Is it inevitable or can it be prevented? Postgrad Med. 2000 Sept; 108(3): 47-52.
• Mazzali G, Di Francesco V, Zoico E, Fantin F, Zamboni G, Benati C, Bambara V, Negri M, Bosello O, Zamboni M. Interrelations between fat distribution, muscle lipid content, adipocytokines, and insulin resistance: effect of moderate weight loss in older women. Am J Clin Nutr. 2006 Nov;84(5):1193-9.
• Effects of estrogen or estrogen/progestin regimens on heart disease risk factors in postmenopausal women. The Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial. The Writing Group for the PEPI Trial. JAMA. 1995 Jan 18;273(3):199-208.
  

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