Are "Diets" a Good Choice for Fertility?

By Beth Heller, MS

The word "diet" can mean "food or drink regularly consumed," or "a regimen of eating and drinking sparsely so as to reduce one's weight." The latter definition is one that inspires fear in the hearts of many who have tried unsuccessfully to lose weight by "going on a diet."One of the most common questions we get at Pulling Down the Moon is “how do general diet programs like Weight Watchers stack up for fertility?”   How diet impacts fertility was also the subject of a daylong symposium at the most recent meeting of the American Society for Reproductive Medicine.  Clearly, overweight is a challenge to fertility and can also block women from access to advanced medical fertility treatments like IVF.  But are diets the answer?

How Do Diets Measure Up?

In our view, for a diet to be fertility-friendly it must a) help women to attain and maintain a healthy weight for fertility b) target the specific ways in which overweight negatively impacts fertility:  poor blood sugar regulation, inflammation and the negative hormonal impact of excess body fat  c) eliminate overly-processed foods and encourage the consumption of minimally processed foods.  So how do "diets" stack up?

A) Help women to attain and maintain a healthy weight for fertility

While it may sound ridiculous, dieting does not seem to be the best way to lose weight.  An extensive 2007 review of weight-loss programs published in American Psychologist concluded that:

Dieters were not able to maintain their weight losses in the long term, and there was not consistent evidence that the diets resulted in significant improvements in their health. In the few cases in which health benefits were shown, it could not be demonstrated that they resulted from dieting, rather than exercise, medication use, or other lifestyle changes. It appears that dieters who manage to sustain a weight loss are the rare exception, rather than the rule. Dieters who gain back more weight than they lost may very well be the norm, rather than an unlucky minority.

Even well established programs like Weight Watchers struggle when we take a closer look at success and maintenance.  There is recent clinical data suggesting that Weight Watchers may be more effective than other diet programs at helping people lose weight and keep it off.   A 2008 study published in The British Journal of Nutrition reported looked at a sample of 976 "lifetime members"(defined as people who met and maintained their goal weight for at least 6 weeks) to see how many remained below their goal weight at 1 (26%), 2 (20.5%) and 5 (16%) years after they successfully completed the program.  On the surface this sounds encouraging but a closer look reveals this study has significant biases that make it next to impossible to generalize the findings.  Only about 6% of people who try Weight Watchers successfully attain and maintain their goal weight and meet the criteria to become lifetime members.  This study looked only at their most successful dieters and only 16% of that already small minority kept the weight off for 5 years.

The other problem with assessing the efficacy of WW is that we do not know what's happening to the other 94% people who try the program and fail.  Are they experiencing the clinically relevant negative effects of dieting, including gaining back more than the weight they lost after a failed diet?

With these numbers in mind, there is a very good chance that many women who are told they need to lose weight in order to increase their odds of pregnancy have already failed at Weight Watchers.  Diets, it seems, are not the answer.

B) Provide ample amounts of nutrients that are important for good nutrition function and target the specific ways in which overweight negatively impacts fertility:  poor blood sugar regulation, inflammation and the negative hormonal impact of excess body fat

Major components of commercial diet programs - eating "low fat," using artificial sweeteners, mass-prepared processed foods to support portion control and optimize convenience and emphasis on low fat dairy and "diet" foods – fly in the face of what we believe lie at the heart of healthy eating in general.  For women to find true success and optimal health they need to “un-learn” many of the dieting habits they have picked up over the years.  This means that frozen processed diet meals are out, as are the sugar-free and low-fat processed snacks.  Diet soda and artificial sweeteners are another crutch that needs to be discarded.  These overly processed food products may conveniently cut calories and “soothe the sweet tooth” (unfortunately artificial sweeteners may actually sharpen a sweet tooth in the long term) but they do not address the underlying causes of infertility – inflammation and poor blood sugar control – associated with overweight.

You can review a head-to-head comparison of a "healthy" low-fat diet versus a fertility-friendly menu in our blog A Tale of Two Diets to learn more about our contention that many of the “healthy” eating habits that have become conventional diet wisdom are simply wrong.   In our estimation an ideal fertility-friendly diet contains about 10% more fat and 10% less carbohydrates than a "typical" healthy diet.  The fats come from foods that naturally have fat in nature - full fat dairy in small amounts, fats from nuts, seeds and oils, as well as fats from grass raised meats and fish in small quantities.  Many of the fat-soluble nutrients and essential oils needed for optimal health are found in these natural fats.

C) Discourage overly processed foods and encourage the consumption of minimally processed foods.

We all seek convenience in our meal preparation but often to the detriment of the food we put in our bodies.  While Jenny Craig, Nutrisystem and Weight Watchers all provide recipes, they  also do a brisk trade in maximally processed meals and snack foods, none of which we feel we could endorse as fertility-friendly.  Processed, packaged in potentially toxic plastics and "fortified" with added vitamins and minerals - they aren't true foods.  Read the ingredients of any of them for a tongue-twisting array of chemicals, preservatives and colorings.

Furthermore, we encourage women who are trying to conceive to eat organic and hormone-free as much as possible. The cardboard, plastic and Styrofoam packaging that wrap up convenience foods and snack-size packs are not good for our environment, either, and may be contributing to the chemical stew that is negatively impacting fertility in the first place.

What's the Solution?

As we mentioned above, most women who have been told they need to lose weight in order to conceive or undergo IVF have likely tried dieting in almost every form possible and do not want to try another one.  So what to do?

Our answer lies in the concept of "nourishing up." Nourishing up is the process of learning how to feed our bodies with real food that includes healthy fats and does not rely on processed low fat, sugar free or diet foods.  With nourishment come satiety, great digestion and optimal nutrition.  In obese and overweight women weight loss is not the goal of nourishing up but it is almost always a by-product.

Our therapeutic intervention for overweight and obesity, First Line Therapy for Fertility, introduces women to highly nutritious and satisfying eating guidelines based on the Mediterranean dietary pattern, which several studies have associated with potential protection against infertility (3, 4).  This dietary pattern emphasizes low-glycemic load, minimally processed foods and healthy oils from vegetable and fish sources.  Refined sugars and treats play a minimal role in this dietary pattern as do "diet foods" like processed low-fat dairy, and sugar free or fat free foods.  First Line Therapy has been shown to promote weight loss as well as improve markers of metabolic syndrome, such as decreasing LDL (bad) cholesterol, in women (5).

Dietitians who have received additional training in fertility nutrition and are up to speed on ART treatments lead the FLTF Program.  We educate women about Fertility Go (eat lots every day), Whoa (okay in moderation) and No (let's skip these) foods, making it easy for women to customize their program to optimize sources of essential fertility nutrients (iron, omega-3 fats, B-vitamins and antioxidants).   In addition there is education and emphasis on foods and supplements that limit inflammation, which is implicated in many different infertility conditions including endometriosis, Polycystic Ovarian Syndrome (PCOS) and poor egg quality. With FLTF, we will help women choose foods that will nourish their bodies with the vitamins and minerals needed to maximize their fertility and help them feel satisfied, while at the same time helping them achieve a healthy weight.

Currently we have two groups of 5 women, one group in Chicago and one in DC Metro, who are participating in the FLTF program.  Stay tuned to our site for more information about their progress, to share their stories, challenges and successes, and to learn more about First Line Therapy for Fertility.

Sources

1.  Mann et al.  Medicare's search for effective obesity treatments:  diets are not the answer. American Psychologist (2007), 62: pp 220 -233.

2.  Lowe et al. Weight-loss maintenance 1, 2 and 5 years after successful completion of a weight-loss programme.  British Journal of Nutrition (2008), 99: pp 925-930.

3.  Toledo et al. Dietary patterns and difficulty conceiving: a nested case-control study.  Fertility & Sterility (2011), 96: 1149-53.

 

4.  Vujkovich et al. The preconception Mediterranean dietary pattern in couples undergoing in vitro fertilization/intracytoplasmic sperm injection treatment increases the chance of pregnancy.  Fertility & Sterility (2010), 94: pp 2096-101.

 

5.  Jones et al. A Mediterranean-style low-glycemic-load diet improves variables of metabolic syndrome in women, and addition of a phytochemical-rich medical food enhances benefits on lipoprotein metabolism.  Journal of Clinical Lipidology (2011) , 5: pp. 188-96.

Categories: Fertility

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