The Low-Carb Conundrum
Low-carb diets are the subject of heated debate in the diabetes community. At first glance, the issue seems cut-and-dried. Carbohydrates cause glucose to rise, so wouldn't a low-carb diet automatically be beneficial for someone with diabetes? But low-carb also turns the traditional food pyramid on its head, and goes against everything the USDA and nutritionists have been saying for the past several decades — that the vast majority of your calories (45 to 65 percent) should come from carbohydrates.
The Pros and Cons
It's an undisputed fact that dietary carbohydrates increase blood sugar levels. Minimize your carb intake, and you'll minimize increases in blood glucose. So low-carb appears to have a logical, though still disputed, place in diabetes management. But what about low-carb for weight loss?
In a nutshell, low-carb proponents blame weight gain on high insulin levels, which can promote fat storage. Since insulin release is triggered by dietary carbohydrates, the reasoning is that too many carbs means too much glucose, which in turn leads to high levels of insulin, which cause fat storage and weight gain.
Fact
One of the most well-known low-carb advocates is Dr. Richard Bernstein, who has type 1 diabetes and helped to pioneer the concept of regular self-monitoring of blood glucose levels. His low-carb, tight-control plan is described in his book, Dr. Bernstein's Diabetes Solution.
The ADA does not endorse Atkins and similar low-carb plans, saying that the high-fat and high-protein content in these diets can be dangerous for people with diabetes who are already at risk for coronary artery disease. The other issue with low-carb diets is that the high-protein content can be tough on the kidneys of people who have advanced kidney disease. The Atkins Center states that no one with severe kidney disease should do the program.
That said, there are many people who swear by such programs — saying that a low-carb diet has given them their blood sugar control back. Most successful low-carbing involves attention to calories as well as carbs; too much fat can add too many calories to your diet, and without calorie reduction, weight loss simply won't occur. If you do decide to give low-carb dieting a try, discuss it with your doctor first, and work with your RD on a customized plan for you.
The issue of the safety of low-carb approaches was high profile enough to warrant a 2000 USDA-sponsored roundtable called “The Great Nutrition Debate,” which pitted low-carb luminaries, including the late Dr. Atkins, against pyramid proponents and other nutritional gurus. Although the conference didn't have any far-reaching policy implications, it did reveal the growing dichotomy between the nutrition establishment and low-carbohydrate advocates.
The Research
In 2003, the New England Journal of Medicine published two controlled trials that put low-carb to the test among people with significant weight and health problems. One study found that obese participants with diabetes who were restricted to 30 grams of carbs daily achieved greater weight loss, maintained better glucose control, and cut triglyceride levels more than their counterparts who were put on a low-fat diet. The second trial had a smaller study population but came to similar conclusions. However, the authors also concluded that the difference in these health benefits between low-fat and low-carb became insignificant after the first six months.
Fact
In 2008, the American Diabetes Association issued its first-ever formal clinical recognition of the potential benefit of low-carb dieting, stating in its nutrition guidelines that low-carb diets “may be effective in the short term” for weight loss.
Subsequent trials have also revealed weight loss and health benefits to low-carb eating. One of these was the A to Z Weight Loss study, which put four popular weight-loss diets — Atkins, Ornish, LEARN, and the Zone — in a head-to-head competition. Results published in the Journal of the American Medical Association in 2007 found that 12 months into the study, those study subjects on the low-carb Atkins program had lost the most weight and achieved the biggest health benefits (in terms of improved cholesterol profiles and lower fasting insulin and glucose levels), as compared to those on the higher-carb alternative diets.
However, a 2006 meta-analysis of studies of low-carb versus low-fat diets for weight loss concluded that while low-carb diets were at least as effective as low-fat diets for weight loss, they were associated with unfavorable changes in total and LDL (bad) cholesterol levels. On a more positive note, the study also found that low-carb dieting was associated with favorable changes in triglyceride and HDL (or good) cholesterol levels.
Alert
Most fad diets are just that — a fleeting fancy. At best, they drain your wallet and your self-confidence; at their worst, they can be hazardous to your health. Any diet that claims dramatic results in days or a few weeks or that relies on “testimonials” instead of hard science is probably destined for failure.
Further long-term, large-scale trials are needed to analyze the risks and potential pluses of low-carb in diabetes treatment. In the meantime, the bottom line is that current research acknowledges the benefits of limiting carbohydrates for weight loss and diabetes control. If you have high LDL or total cholesterol, your doctor should monitor your cholesterol levels carefully if you choose to go on a low-carb diet.
Glycemic Index Diets
And then there's the glycemic index, the subject of many best-selling diet books and another dietary hot potato. The GI focuses on the choice of carbs rather than carb restriction. Low-GI foods raise blood glucose levels at a slow and steady rate, promoting weight loss by discouraging blood sugar spikes and high circulating levels of insulin. The GI has a solid foundation in science and many faithful followers, but requires some dedicated math skills and an even more dedicated patient.
