Obesity is presently a worldwide epidemic. U.S.-based population surveys estimate that 51.7% of non-pregnant women aged 20-39 are overweight or obese (Ogden et al., 2006). A recent article in The Lancet reported that 30% of the world population is currently overweight or obese (No, Fleming, Robinson, et al. (2014). While the U.S. includes 5% of the world population, it has 13% of the world’s overweight and obese population. Further, the authors report that no country has lowered its rate of obesity in the past 33 years. Thus, while this is a public health priority, is it fair to single out and apply restrictions to infertile obese women when no such prohibition to procreation is applied, nor could be applied, to fertile obese women?
Millions of dollars are spent annually on weight loss efforts. Long-term results are disappointing, with the majority of dieters regaining as much or more of the weight they lost (Ayyad & Andersen, 2000). While weight loss depends on a combination of increased energy expenditures through exercise and decreased energy intake through caloric restriction, people rarely choose to become overweight and just telling someone to eat less and exercise more, something they have probably heard countless times before, is a recipe for failure.
How Does Excessive Weight Alter Reproductive Function?
The hormones testosterone and estradiol accumulate in body fat. These hormones have a metabolic effect on the hypothalamic-pituitary axis of the brain which is involved in reproductive function. An overabundance of these hormones can have the net effect of impairing reproductive function. Both thin and obese women may have problems in reproductive function, but by different mechanisms, thin women having a deficiency and obese women having an excess of estrogen. Data suggests that obese men may also experience endocrine dysfunction which may alter their semen parameters as well as their retention and metabolism of environmental toxins, all of which may contribute to an increase in male infertility (Hammoud et al., 2008)
What are Possible Signs of Altered Reproductive Function in Women?
• Variation from an established, regular, and predictable menstrual cycle
• Lack of abundant clear mucous secretion from the vagina at mid-cycle, suggesting a lack of ovulation
• Increased hair on the lower abdomen, face, and between the breasts, due to an increased production of androstenedione, a weak male hormone but one which, over time, will stimulate excessive body hair growth
The typical weight loss may be insufficient to allow many women to cross an arbitrarily chosen body mass index (BMI) threshold, although even a modest weight loss of 5-10% of body weight can offer health benefits and may improve fertility potential (Balen et al., 2007). While lifestyle modifications are associated with positive rates of compliance, the weight loss which occurs initially may be too slow for women who are racing against their loudly ticking biological clock.
Obesity is a complex multisystem disease with many potential triggers, for example, metabolic disorders, hormone imbalances, medication, psychological issues, and physical injuries, and each individual is a unique puzzle with many hidden causes of weight gain. If a woman is already obese, she needs education, a multidisciplinary team including psychological support and specialists in nutrition, exercise, and behavioral interventions who are familiar with issues for obese infertile women (e.g., PCOS) and can help her create a realistic plan and provide encouragement, understanding and praise for accomplishing weight reduction, and ongoing support to monitor, motivate, and counter recidivism. To counter abandonment of her efforts, a woman must be realistically informed that weight loss doesn’t always occur immediately, with one pound per week a realistic expectation. Obese individuals should set their ultimate goal at 110% of predicted ideal body weight, as aiming for a weight that is too low tends to cause frustration and abandonment of one’s efforts and is almost impossible to maintain.
Nothing seems to work on a long-term basis, however, without including behavior modification and a lifestyle based system. Behavioral strategies that can assist include:
• Self-monitoring – this encourages accurate portrayal of baseline weight and food intake with objective monitoring of changes over time.
• Stimulus control – modify one’s environment to promote behaviors consistent with one’s goals, e.g., increase the availability of healthy foods, decrease the availability of unhealthy foods, have home delivery of groceries to help reduce impulse purchases, place sneakers in a high visibility area to serve as a visual cue to become more physically active.
• Nutritional education and meal planning – plan meals in advance as this reduces giving in to temptation; include variety to avoid boredom.
• Slow down your rate of eating – sit down when you eat and put your fork down every one-three bites; eat more consciously, savoring each bite. This allows you to feel satiated before overeating.
• Set realistic goals – short-term, reasonable weight loss goals with a long-term outlook, preferably setting a goal of five pounds at a time, then go for the next five (overweight individuals typically initiate treatment desiring losses 2-3 times greater than this, and this typically results in less weight loss). Work on portion control, reducing portions initially by ¼ and eventually by ½, and sustain this after reaching your end goal.
• Increase physical activity – consider wearing a pedometer to challenge yourself to add extra steps every day, ultimately aiming for 10,000 steps per day. Exercise has the additional advantage of improving mood and has a positive influence on self-regulation of eating behavior, as well. To increase your motivation to exercise, check out http://www.sleeplikethedead.com/exer-1--benefits.html
• Relaxation training – to help manage negative affect which makes healthy lifestyle choices more likely.
• Enlist social support – implement behavioral contracting and find someone with good problem solving abilities to keep you accountable and provide support. You can share only your weekly change in weight rather than your actual weight if this is more comfortable for you.
• Be informed and utilize cognitive behavior therapy techniques for maladaptive cognitions regarding weight loss, food, hunger, and self-esteem. To increase the likelihood of sticking to your plan, be aware that: weight loss becomes less pronounced with time; you won’t lose weight every week even if strictly adhering to your plan; and variation in diet and exercise is important to counter boredom.
A good book to help you learn to identify and respond to dysfunctional thoughts that may interfere with sticking with your plans for dietary intake and exercise (e.g., all-or-nothing thoughts such as, “Feeling full is good, feeling hungry is bad”; “I must be perfect on my diet, else all is lost and I might as well eat anything I want”; “Once I lose weight I can return to the way I used to eat”) is The Beck Diet Solution by Judith Beck. Prepare for feeling frustrated and discouraged at times, but have a list of the advantages of sticking with your plan in an easily-accessible location. Anticipate slips or lapses, they are the norm. But think about how to prepare for these so you can prevent a lapse from becoming a permanent return to a previously undesired behavior.
It is outside the scope of this blog to review psychopharmacological or bariatic surgery interventions.
In conclusion, there is currently insufficient evidence to link a high BMI with reduced birth rates to deny access to infertility treatment for overweight women (Maheshwari et al., 2007). In fact, body fat distribution as measured by waist circumference divided by hip circumference may be a better predictor of reproductive outcome for women than BMI (Wass et al., 1997; Zaadstra et al., 1993). Prevention is truly the best approach. However, until that is attained, all overweight women should be informed of the overall health and obstetric risks prior to conception, not just the infertile, and those seeking fertility care should be informed of their slightly lower success rates using IVF. Those who have sufficient time and motivation to lose weight prior to IVF should be encouraged to do so, but not discriminated against. Individual judgment must be used to balance the improvement in live birth rates associated with weight loss in older women against the much steeper losses of fertility with age.
Ayyad, C, Andersen, T. Long-term efficacy of dietary treatment of obesity: a systematic review of studies published between 1931 and 1999. Obes Rev, 2000; 1: 113-19.
Balen AH, Anderson RA. Policy & Practice Committee of the BFS. Impact of obesity on female reproductive health: British Fertility Society, Policy and Practice Guidelines. Hum Fertil (Camb). 2007; 10(4): 195-206.
Beck, J. The Beck Diet Solution. Birmingham, AL: Oxmoor House, 2007.
Hammoud, AO, Gibson, M, Peterson, CM, Meikle, AW, Carell, DT. Impact of male obesity on infertility: a critical review of the current literature. Fertil Steril, 2008; 90(4): 897-904.
Maheshwari, A, Stofberg, L, Bhattacharya, S. Effect of overweight and obesity on assisted reproductive technology-A systematic review. Hum Reprod Update; 2007; 13: 433-44.
Metwally, M, Li, TC, Ledger, WC. The impact of obesity on female reproductive function. Obes Rev, 2007; 8(6): 515-23.
Ogden, CL, Carroll, MD, Curtin, LR, McDowell, MA, Tabak, CJ, et al. Prevalence of overweight and obesity in the United States, 1999-2004. JAMA, 2004; 295: 1549-55.
Wass, P, Waldenstrom, U, Rossner, S, Heilberg, D. An android body fat distribution in females impairs the pregnancy rate of in vitro fertilization-embryo transfer. Hum Reprod, 1997; 12: 2057-60.
Zaadstra, BM, Seidell, JC, Van Noord, JC, te Velde, ER, Habbema, JD, et al. Fat and female fecundity: prospective study of effect of body fat distribution on conception rates. Br Med J, 1993; 306: 484-87.