Good post on how estrogens, when they are reduced by perimenopause and menopause, lower your metabolic rate. Unfortunately, this can start at early as age 35-40. Welcome to Perimenopause, My Friends! But there are things we can do about it. Read on....
Question: Does exercise attenuate or prevent the weight gain that occurs during peri- and post-menopause?
Commentary from:
Wendy M. Kohrt, PhD
Professor of Medicine
University of Colorado, Denver
in Menopause E-consult by the North American Menopause Society
The short answer is, yes, exercise can attenuate
or prevent weight gain during peri- and
postmenopause. The prevention of weight gain
at any age requires only that energy intake not
exceed energy expenditure. Thus, it is possible
to maintain body weight by modifying exercise
and/or eating habits. However, although simple
in theory, there are physiologic changes that
make it particularly challenging for middle-aged
women to maintain energy balance (ie, intake =
expenditure). Because the menopause transition
occurs over a number of years, it is difficult to
determine whether the increased propensity for
weight gain at midlife is primarily a
consequence of the menopause transition or of
advancing age. Both involve factors that make
weight maintenance a challenge.
Menopause-related factors that promote weight
gain. Studies of laboratory animals provide
compelling evidence that estrogen plays an
important role in the regulation of body weight.
Oophorectomy has consistently been found to
cause excess weight gain, and this is prevented
by estrogen replacement.1 There appear to be
multiple mechanisms by which estrogen
deficiency leads to weight gain in animals,
including increased food intake, decreased
spontaneous physical activity, and a suppression
of metabolic rate. If such effects of estrogen
deficiency also occur in humans, this would
suggest that there is a “biological drive” around
the time of menopause toward weight gain.
In fact, there is evidence that estrogen regulates
body weight in women. A number of large,
randomized, placebo-controlled, and open-label
trials of estrogen-based hormone therapy (HT)
have provided strong evidence that weight gain
and, more specifically, fat gain, is attenuated in
women on HT when compared to women on
placebo or no HT.2 Suppressing sex hormone
levels in premenopausal women with
gonadotropin-releasing hormone (GnRH)
agonist therapy also causes fat gain. For
example, women treated for 16 weeks with a
GnRH agonist gained 1.0 kg of fat, which
equates to an energy excess of about 80 kcal per
day.3 Because it is difficult to accurately
measure changes in energy intake and
expenditure of this magnitude in humans, it is
not clear whether the suppression of sex 2
hormones influences eating and/or exercise
habits. However, short-term hormone
suppression has been found to cause a decrease
in resting metabolic rate of 40 to 70 kcal per
day.4 This reduction in metabolic rate would be
expected to cause weight gain if not
accompanied by a compensatory decrease in
energy intake or increase in physical activity.
Aging-related factors that promote weight gain.
Even if the menopause transition does not alter
bioenergetics in a way that promotes weight
gain, there are unavoidable factors related to
aging that do so. Two important factors are the
loss of muscle mass and the decline in maximal
aerobic power. Lean body mass is an important
determinant of resting metabolic rate. As lean
mass declines with aging, there is a decrease in
metabolic rate and, therefore, daily energy
expenditure. The decline in metabolic rate will
result in weight gain unless appropriate
behavioral changes are adopted (ie, decrease in
energy intake or increase in physical activity).
Maximal aerobic power, also referred to as
aerobic capacity or VO2 max, is a direct index of
the rate at which an individual can expend
energy during exercise. For example, a healthy
young woman with an average VO2 max for her
age can easily increase her energy expenditure
by 8 to 10 kcal per minute during exercise.
However, there is a decline in VO2 max with
aging that cannot be avoided, due in part to the
inevitable decrease in maximal heart rate (ie,
maximal heart rate = 220 minus age).
Accordingly, with advancing age there is a
decline in the rate at which energy can be
expended during exercise, even in people who
maintain a vigorous level of physical activity.5
Rather than being able to increase energy
expenditure by 8 to 10 kcal per minute during
exercise, middle-aged women may be able to
burn only 6 to 8 kcal per minute. This has an
important impact on how women can use
exercise to maintain body weight as they age.
Because the rate at which energy can be
expended decreases gradually with aging,
maintaining the same level of total exercise
energy expenditure may require an increase in
the amount of exercise time.
Do physically active women gain less weight
than sedentary women during peri- and
postmenopause? Exercise can prevent weight
gain in peri- and postmenopausal women, but
factors related to menopause and aging make
weight maintenance a challenge. Even though
regular exercise does not come with a guarantee
against weight gain, prospective studies of
perimenopausal women indicate that the most
active women gain the least weight.6,7 Most
important, women should not abandon their
exercise habits if they become discouraged by
what they perceive as a lack of effectiveness of
exercise to prevent weight gain. Exercise has
numerous health benefits that are independent of
its effects on body weight regulation.8
Disclosure: Dr. Kohrt reports: Research support—
National Institutes of Health.
References:
1. Shi H, Clegg DJ. Sex differences in the regulation of
body weight. Physiol Behav 2009 Feb 27. [Epub ahead of
print]
2. Lobo RA. Metabolic syndrome after menopause and
the role of hormones. Maturitas 2008;60:10-18.
3. Yamasaki H, Douchi T, Yamamoto S, Oki T,
Kuwahata R, Nagata Y. Body fat distribution and body
composition during GnRH agonist therapy. Obstet
Gynecol 2001;97:338-342.
4. Day DS, Gozansky WS, Van Pelt RE, Schwartz RS,
Kohrt WM. Sex hormone suppression reduces resting
energy expenditure and beta-adrenergic support of resting
energy expenditure. J Clin Endocrinol Metab 2005;90:
3312-3317.
5. Hawkins SA, Marcell TJ, Victoria JS, Wiswell RA.
A longitudinal assessment of change in VO2 max and
maximal heart rate in master athletes. Med Sci Sports
Exerc 2001;33:1744-1750.
6. Sternfeld B, Wang H, Quesenberry CP Jr, et al.
Physical activity and changes in weight and waist
circumference in midlife women: findings from the Study
of Women’s Health Across the Nation. Am J Epidemiol
2004;160:912-922.
7. Macdonald HM, New SA, Campbell MK, Reid DM.
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 Relat Metab
Disord 2003;27:669-676.
8. Haskell WL, Lee IM, Pate RR, et al. Physical activity
and public health: updated recommendation for adults
from the American College of Sports Medicine and the
American Heart Association. Circulation 2007;116:1081-
1093.
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