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Weight Loss, Type 2 Diabetes, and the Importance of a Diet That "Fits"

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Weight Loss, Type 2 Diabetes, and the Importance of a Diet That “Fits”

It’s natural for most of us to get caught up in the debate over diets and which ones are “best.” Researchers get caught up in this issue as well, particularly when it comes to chronic disease situations like obesity and type 2 diabetes. Many different approaches to diet can help us lose weight-at least in the short-term. But in type 2 diabetes, there is also a need to improve insulin metabolism and blood sugar levels.

Researchers at the Albert Einstein College of Medicine at Yeshiva University in the Bronx, NY put two very different diet approaches to the test in their study of 105 obese adults, mostly Hispanic and African-American, who were on medication for their type 2 diabetes. Half of the participants in this study followed a very low carbohydrate diet, based upon the Atkins diet. (In this diet, the participants were allowed only 20-25 grams of carbohydrate per day during the first 2 weeks. After that time, they were allowed to increase their carbs each week by a total of 5 grams.) The other group of participants followed a low-fat diet in which a maximum of 25% total calories were allowed from fat. (For example, if a participant were allowed to eat 1,600 calories of food, 44 grams of fat could come from fat. That amount is the same as 2 tablespoons of olive oil plus 1 ounce of walnuts.) Over the course of one year, all participants received regular nutritional counseling and assistance following their diet plans.

The results of this study were extremely interesting. Overall, participants in both groups lost weight over the 12-month study period. Their average weight loss was approximately 7 pounds, or 3.5% of their initial body weight. However, the low-carb group lost weight rapidly in the first three months (for a total of about 11 pounds) and then regained weight very slowly (at about one-half pound per month) over the rest of the study period. The low-fat group lost weight more slowly over the first three months (for a total of about 7.5 pounds), and then plateaued and just stopped losing weight. Neither group significantly improved their blood sugar levels (as determined by lab work measuring their hemoglobin A1C). In their discussion of the blood sugar results, the researchers noted that in previous studies, a total weight loss of about 10-15 pounds was required before significant changes could be observed in hemoglobin A1C levels.

The research team in this study concluded that very low carbohydrate and low fat diets could be helpful to obese individuals with type 2 diabetes who were trying to lose weight and control their blood sugars, but that the helpfulness of these diets might be limited unless practical aspects of the diets were made very familiar to the participants and could be followed closely for an extended period of time. In other words, they recognized the fact that very low carb diets and low fat diets can be very challenging to follow, and while potentially helpful might not turn out to be as helpful as expected due to practical difficulties in adherence.

We definitely agree that very low carb diets and low fat diets can present real difficulties as long-term, everyday approaches to eating. A daily intake of 20-25 grams of carbohydrate is a very unnatural food balance, which makes it impossible to enjoy fruits, vegetables, whole grains, and legumes. Additionally, 25% fat is likely to be a level that many people find unnaturally restrictive. If you use up 33% of your day’s fat with one tablespoon of olive oil, your options with nuts, seeds, and cold-water fish become pretty limited.

So we would go one step further than these researchers in our interpretation of the study results. We would conclude that very low carb and low-fat diet approaches are probably not helpful to most individuals because they create a diet context that is just too unnatural. Most people are unlikely to stick with any diet that feels too unnatural, regardless of the diet. The world of food is diverse and rich in foods of all flavors and textures, and a diet needs to contain enough nutritional room for us to enjoy all of them!

From a long-term perspective, the only approach that makes sense to us is one that allows for complete individualization of a diet in a way that feels natural to the person following it. In most cases, that kind of individualization will mean more room for high-quality carbs and high-quality fats than was allowed in either of the diets featured in this study.

WHF Recommendations

Whether you are a healthy individual without existing chronic disease, or an individual who is obese and on medication for type 2 diabetes, you will need to find a diet approach that is enjoyable and feels natural to you. You will most likely have to give yourself enough room in your diet for however many carbs and fats it takes to enjoy the flavors and textures of whole, natural foods. Placing unnatural restrictions on your diet may work in the short term, but it is unlikely to keep you healthy in the long run.

References

References

  1. Davis NJ, Tomuta N, Schechter C et al. v. Comparative study of the effects of a 1-year dietary intervention of a low-carbohydrate diet versus a low-fat diet on weight and glycemic control in type 2 diabetes. Diabetes Care. 2009 Jul;32(7):1147-52. 2009.