Obesity is a pandemic that’s well known. Obesity is often defined as BMI ≥30. Worldwide, about twice as many women as men suffer from severe obesity. In healthy-weighted women, the absolute fat distribution becomes obvious only after puberty.
Studies have revealed women-specific factors in the two physiological determinants of obesity,
- the extent of energy intake (eating) and
- the level of energy expenditure.
Eating and weight management are special challenges for women’s health. The intake of metabolic energy occurs mainly in the form of meals (including snacks). Reproductive hormones importantly modulate these physiological controls of eating.
Menstrual cycle and eating pattern
The eating pattern of a woman changes during the menstrual cycle. Studies demonstrated that eating decreases through the follicular phase (The time between the first day of the period and ovulation) to a minimum during the periovulatory phase and are similarly high during the early-follicular and luteal phases (the second half of your menstrual cycle).
Available data indicate that eating does not decrease during anovulatory cycles and that the decrease in ovulatory cycles is due to decreased meal size rather than decreased meal frequency.
Sex differences in food selection did appear, however, in surveys of obese persons. Obese women ate more high-sugar, high-fat foods (median intake ∼146 g/day of cakes, chocolate, etc.) than obese men (∼103 g/day), leading to a higher sugar intake (21 vs. 17% of daily energy).
Overeating more prevalent in women
Ovarian hormones (estrogen, progesterone) become prominent in girls during puberty and have been found to predict changes in food intake. Estradiol may be one important moderator of genetic effects on disordered eating during puberty.
Binge eating, referring to eating an abnormally large amount of food on a single occasion with a feeling of loss of control overeating, is a dysregulated form of eating especially prevalent in girls and women. Related to binge eating is emotional eating, i.e. eating in response to negative emotions is also more prevalent in girls and women.
Binge eating develops most often during puberty, in association with higher estrogen levels.
Sex hormones increase weight
Despite their prominent roles in the control of reproduction, estrogens pervade many other bodily functions. Estrogens play a fundamental role in the physiology of the reproductive, cardiovascular, skeletal, and central nervous systems. Estrogen influences both eating and energy expenditure in women. Estrogen is a potent modulator of energy balance, as evidenced in extreme conditions of estrogen deficiency characterized by an increase in the desire to eat and decreased energy expenditure, and leading to obesity.
Some studies related to the effects of hormonal contraceptives (Progestin-only contraceptives) on weight have shown a slight increase in body fat and body weight. Weight gain is often considered a side effect of using hormonal contraceptives. Actual mean weight gain was limited at 6 or 12 months, i.e., less than 2 kg for most studies.
Interestingly, weight increase seems to occur only in girls who are healthy-weight when initiating treatment, but not in girls who are already overweight. And in younger postmenopausal women (age 50–59 y), estrogenic hormone therapy reduces fat mass.
Obesity and PCOS
Obesity is considered as the characteristic of polycystic ovary syndrome (PCOS). Some studies suggest that PCOS is associated with greater abdominal obesity. Obese patients with the peripheral distribution of fat have a relatively low CV and metabolic risk. Also, obesity, especially abdominal obesity, disrupts ovarian cycling and leads to signs of hyperandrogenism, obesity is presumed to cause or exacerbate PCOS.
There is a dearth of research on the influence of reproductive hormones on these controls of eating. If these hormones are in control then the binge effect and other causes of weight gains will be reduced.
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