The coming of the fit at forty


Menopause and Weight Gain

There is some controversy regarding weight gain around the time of menopause. There are suggestions that at the onset of menopause a woman's body weight reaches its maximum and for any given subsequent body weight there is an increase in relative body fat and abdominal fatness with advancing age (1). This increase in body fat in the abdominal region is related to an increase risk of heart disease, diabetes and certain cancers. Is this weight gain inevitable and what are the primary causal factors? Are hormonal changes, or lifestyle factors more important?

Some of the proposed causes of weight gain during menopause include, a reduction in metabolic rate that reduces the utilisation of calories and hence increases body weight, and reductions in oestrogen levels. Others claim that lifestyle factors such as physical exercise and not hormonal factors have greater influence over weight gain in older women.

Not all studies show a consistent increase in body weight in women during the transition of menopause. This may be because of important differences in study design, such as retrospective assessment of age at menopause and failure to control for confounding factors.

While weight gain is common in mid-life among women, most studies do suggest that it is not related to the transition of menopause and the changes in hormones. It is suggested that weight gain is associated with age, not menopause. It has been proposed that while menopausal transition affects body mass index in mid-life, the effect is small relative to other influences (2). Other studies suggest that while weight change occurs independent of menopausal status, adverse changes in body fat distribution and body composition may be due to hormonal changes occurring during the menopausal transition (3).

A consistent finding in the studies on weight gain around the time of menopause is the importance of physical activity (2-6). To avoid weight gain, women should make regular physical activity a priority.

A cohort of 418 females from the Women's Health Study was used to assess the relationship between menopause transition and weight, after accounting for previous weight; age; and the behavioural factors of smoking, exercise, and annual ethanol consumption (7). In this study, menopause transition was not consistently related to weight gain. Behaviour factors, in particular exercise and alcohol intake were more strongly related to weight gain than was the menopause transition. The authors of this study concluded that the results are consistent with findings from other studies that suggest that the weight increases experienced by middle-aged women in the United States are not a result of the menopause transition.

Overall, according to cross-sectional observational studies postmenopausal women with high levels of physical activity have lower body fat and abdominal fat. Longitudinal studies show that physically active women are less likely to gain body fat and abdominal fat after menopause than sedentary women. Unfortunately there are very few randomised controlled trials (RCT) investigating exercise per se and diet and exercise. Therefore there is a need for randomised clinical trials to evaluate the effect of increased physical activity and fitness for prevention of the changes in body composition associated with menopause and aging in normal weight women.

In conclusion, weight gain and increased waist circumference, along with elevations in lipid levels and other heart disease risk factors appear preventable through use of lifestyle intervention in healthy menopausal-aged women. Given the prevalence and chronic course of obesity, weight gain prevention should be recognized as an important health goal for women before they approach menopause. Interventions to increase physical activity and the consumption a nutrient dense diet containing appropriate calories are highly recommended to prevent increases in adiposity common in mid-life.

Recommendations for women entering menopause

  • It is important to note that weight gain is not inevitable
  • Physical exercise is an important factor which can prevent weight gain with age and therefore should be encouraged
  • To maintain body weight women must ensure that their dietary intake of calories does not exceed their energy expenditure


Potential benefits of soy intake

Weight gain and complications
There is some evidence that phytoestrogens (found in soy foods for example) may play a beneficial role in obesity and diabetes (8).
It has been suggested that soy proteins may improve obesity by inhibiting insulin secretion or by inhibiting lipogenesis and enhancing lipolysis in the adipocytes. Most human studies to date however have not shown a decrease in body fat as a result of the ingestion of soy (9-12).
Increased adiposity with ageing often occurs in the intra-abdominal region. This can increase the risk of diabetes and heart disease. Several studies have suggested that soy may protect against heart disease. It is unclear which component/s of soy may exert the beneficial effects. Potential components may include the soy protein, isoflavones, and fibre.
It has been suggested that soy isoflavones may beneficial for diabetic subjects because of their estrogenic activity and their ability to prevent glucose-induced lipid peroxidation and inhibit intestinal glucose uptake (13).
Much of this research has been conducted in vitro (i.e. not in the body). In addition, the trials that have been conducted have been largely observational, of short duration, with small numbers of participants. Further clinical trials are required to see if increased soy intake protects against the negative effects of increased abdominal fat.

Osteoporosis
The data on the effects of soy on bone mineral density are limited, but some short-term human studies show a small protective effect at the spine (14,15). Animal studies also show that soy-rich diets prevent bone loss (16-20).

Menopausal symptoms
Some studies suggest that increased soy consumption, especially when usual intake is low, may relieve some of the symptoms of menopause (21-25). The research however is still equivocal (26-28).

References:

  1. Astrup A. Physical activity and weight gain and fat distribution changes with menopause: current evidence and research issues. Med Sci Sports Exerc. 31:S564-567, 1999.
  2. Mathews K.A., Abrams B., Crawford S.L., Miles T., Neer R., Powell L.H. and Wesley D. Body mass index in mid-life women: relative influence of menopuse, hormone use, ethnicity. Int J Obes & Related Metab Dis. 25:863-873, 2001.
  3. Simkin-Silverman L.R. and Wing R.R. Weight gain during menopause. Is it inevitable or can it be prevented? Postgraduate med. 108:47-50, 2000.
  4. Campbell L.V. and Samaras K. What is the evidence, reasons for and impact of weight gain during menopause. Med J Aust. 173:S100-S101, 2000.
  5. Dubnov G., Brzezinski A. and Berry E.M. Weight control and the management of obesity after menopause: the role of physical activity. Maturitas. 44:89-101, 2003.
  6. MacDonald H.M., A N.S., Campbell M.K. and Reid D.M. Longitudinal changes in weight in perimenopausal and early postmenopausal women: effects of dietary energy intake, energy expenditure, dietary calcium intake and hormone replacement therapy. Int J Obes & Related Metab Dis. 27:669-676, 2003.
  7. Crawford S.L., Casey Y.A., Avis N.E. and McKinlay S.M. A longitudinal study of weight and the menopause transition: results from the Massachusetts Women's Health Study. Menopause. 7:96-104, 2000.
  8. Bhathena S.J. and Velasquez M.T. Beneficial role of dietary phytoestrogens in obesity and diabetes. Am J Clin Nutr. 76:1191-1201, 2002.
  9. Bosello O., Cominacini L. and Zocca I. Short- and long-term effects of hypocaloric diets containing proteins of different sources on plasma lipids and apoproteins of obese subjects. Ann Nutr Metab. 32:206-214, 1998.
  10. Jenkins D.J.A., Wolever T.M.S. and Spiller G. Hypocholesterolemic effect of vegetable protein in a hypocaloric diet. Atherosclerosis. 78:99-107, 1989.
  11. Mikkelsen P.B., Toubro S. and Astrup A. Effect of fat-reduced diets on 24-h energy expenditure: comparisons between animal protein, vegetable protein, and carbohydrate. Am J Clin Nutr. 72:1135-1141, 2000.
  12.  Yamashita T., Sasahara T., Pomeroy S.E., Collier G. and Nestel P.J. Arterial compliance, blood pressure, plasma leptin, and plasma lipids in women are improved with weight reduction equally with a meat-based diet and a plant-based diet. Metabolism. 47:1308-1314, 1998.
  13. Vedavanam K., Srijayanta S. and O'Reilly J. Antioxidant action and potential antidiabetic properties of an isoflavone-containing soyabean phytochemical extract (SPE). Phtyother Res. 13:601-608, 1999.
  14. Alekel D.L., St Germain A., Pereson C.T., Hanson K.B., Stewart J.W. and Toda T. Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women. Am J Clin Nutr. 72:844-852, 2000.
  15. Potter S.M., Braum J.A., Teng H., Stillman R.J., SHAY N.F. and Erman J.W. Soy protein and isoflavones: their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr. 68:1375S-1379S, 1998.
  16.  Anderson J.J. and Garner S.C. Phytoestrogens and bone. Bailieres Clin Endocrinol Metab. 12:543-557, 1998.
  17. Arjmandi B.H., Alekel D.L., Hollis B.W., Amin D., Stacewicz-Sapuntzakis M., Guo P. and Kukreja S.C. Dietary soybean protein prevents bone loss in an ovariectomized rat model of osteoporosis. J Nutr. 126:161-167, 1996.
  18.  Arjmandi B.H., Birnbaum R., Goyal N.V., Getlinger M.J., Juma S., Alekel L., Hasler C.M., Drum M.L., Hollis B.W. and Kukreja S.C. Bone-sparing effect of soy protein in ovarian hormone-deficient rats is related to its isoflavone content. Am J Clin Nutr. 68, 1998.
  19. Ishimi Y., Miyaura C., Ohmura M., Onoe Y., Y S., Uchiyama Y., Ito M., Wang X., Suda T. and Ikegami S. Selective effects of genistein, a soybean isoflavone, on B-lymphopoiesis and bone loss caused by estrogen deficiency. Endocrinology. 140:1893-1900, 1999.
  20. Picherit C., Bennetau-Pelissero C., Chanteranne B., Lebeque P., Davicco M.J., Bartlet J.P. and Coxam V. Soybean isoflavones dose-dependently reduce bone turnover but do not reverse established osteopenia in adult ovariectomized rats. J Nutr. 131:723-728, 2001.
  21. Brzezinski A., Adlecreutz H., Shauol R., Rosler A., Shmueli A., Tanos V. and Schenker J.G. Short-term effects of phytoestrogen-rich diet on postmenopausal women. Menopause. 4:89-94, 1997.
  22. Han K.K., Soares J.M., Haider M.A., de Lima G.R. and Baracat E.C. Benefits of soy isoflavone therapeutic regimen on menopausal symptoms. Obstet Gynecol. 99:389-394, 2002.
  23. Nagata C., Takatsuka N., Kawakami N. and Shimizu H. Soy product intake and hot flushes in Japanese women: results from a community-based prospective study. Am J Epidemiol. 153:790-793, 2001.
  24. Somekawa Y., Chiguchi M., Ishibashi T. and Aso T. Soy intake related to menopausal symptoms, serum lipids and bone mineral density in postmenopausal Japanese women. Obstet Gynecol. 97:109-115, 2001.
  25. Upmalis D., Lobo R., Bradley L., Warren M., Cone F.L. and Lamia C.A. Vasomotor symptom relief by soy isoflavone extract tablets in postmenopausal women: a multicentre, double-blind, randomized, placebo-controlled study. Menopause. 7:236-242, 2000.
  26. Baber R.J., Templeman C., Morton T., Kelly G.E. and West L. Randomized placebo-controlled trial of an isoflavone supplement and menopausal symptoms in women. Climacteric. 2:85-92, 1999.
  27. Dalais F.S., Rice G.E., Wahlquist M.L., Grehan M., Murkies A.L., Medley G., Ayton R. and Strauss B.J.G. Effects of dietary phytoestrogens in postmenopausal women. Climacteric. 1:124-129, 1998.
  28. Knight D.C., Howes J.B. and Eden J.A. The effect of Promensil, an isoflavone extract, on menopausal symptoms. Climacteric. 1166-1174, 1999.