Carbs – how low do you have to go for weight loss and health gain?

Anyone who reads the medical journals knows that study after study are slaughtering the idea that low-fat, low calorie diets are best for weight loss, diabetes and heart disease prevention. Far better are either very low Atkins-style carbohydrate diets, or very low GL diets.

In the very low carb diets people eat more protein and more fat, but very small amounts of carbohydrates, usually in the order of less than 130 grams. That’s less than a serving of rice, pasta or potatoes, so these kind of foods are off the menu. There’s growing evidence that this approach, although difficult to maintain long-term because we like eating carbs, really does work for people with diabetes and heart disease, as well as weight loss, dramatically reducing need for medication. The reason why this approach works is that these very low carb diets really do stabilise your blood sugar – and that’s the key. (A.Accurso et al, Nutrition and Metabolism, 2008, 5:9) The die hard low-calorie brigade have slightly modified their view in recent years, not by cutting back on total carbohydrates, but by recommending slow-releasing or low-GI (Glycemic Index) carbs.

While a step in the right direction this isn’t enough to make a big difference. One step further is a low GL diet which has the net effect of stabilising blood sugar, but without the extreme restriction on carbohydrates. GL (Glycemic load) is a much more precise thing than just eating low GI foods. The GL of a meal is worked out both by knowing how much carbs are in the meal, and how fast-releasing those carbs are. So it factors in both the quantity of carbs and the quality of carbs. Put another way, you can stabilise your blood sugar by either eating very little carbs (a low carb diet) or by only eating carbs that release their sugars slowly (such as oats). When your GL intake is down to 40 a day, which is what I recommend in my low GL diet, then you get most of the benefits reported from very low carb diets. But it is a precise, and doable, thing.

My books show exactly the GL of specific foods and meals, aiming for 10GLs for main meals, and 5 GLs for snacks. But which works better? One study compared a low GL diet (not as low as mine) with a low carb diet and found that fat loss in women was higher on the low GL diet, and weight loss was fractionally higher in low carb diet. (J McMillan-Price et al., Archives of Internal Medicine, Vol 166 (2006), pp. 1466-1475) So, both worked. The advantage of a low gL diet is that it is more sustainable. People often tell me “it’s not a diet. It’s just become my way of life.” They feel so good, and love the foods, that this way of eating is easily sustained. For weight loss I’d favour a strict low GL diet. F

or reversing diabetes and heart disease, both a low carb diet and a strict low GL diet work. If you choose the former for a few months, it’s really important to then stabilise on a lowGL diet if you can’t stomach all that protein and fat. Of course, the big downside of most low carb diets is their reliance on animal and dairy protein. A high intake of these is linked to increased cancer risk, especially of the breast and prostate. That’s what makes me cautious of following low carb diets on a long-term basis. Of course, few studies measuring the effects on indicators of diabetes or heart disease are long enough to truly assess changes in cancer incidence. If you’d like to find out more about low-GL why not book a ticket to come to one of the seminars on my GL Revolution Tour this April. Click here to find out more.