Slow Carb Not Low Carb
In May, ‘News Brief’ reported on a woman who was hospitalised for life-threatening ketoacidosis after following the Atkins diet. We then listed the reasons why we advocated a low GI diet rather than a low carbohydrate diet. Some of our readers admonished us for our stance. Here are their comments and our responses.
- Opposers of low carb regimes tend to stick to criticism that are really directed to the so called ‘induction phase’ which lasts only two weeks. After that, dieters on Atkins can and should consume a great variety of green, leafy nutritious vegetables, among many others, like mushrooms, eggplant, peppers, broccoli, cauliflower etc. Atkins never encourages you to eat zero carbs. 20 grams for the first 2 weeks, and you raise those levels after that.
Yes, that’s true, criticism is often aimed at the induction phase but it’s also true that the second phase is restricted in carbohydrates (around 50 grams a day) too, and adherents are encouraged to return to the induction phase (20 grams a day) if weight loss slows. Furthermore, because Atkins recognised that the diet was not nutritionally balanced, a vitamin and mineral supplement program is compulsory.
The study by Yancy et al (Annals of Internal Medicine 2004: 140; 769) compared an Atkins diet with a prudent (low fat but high GI) diet in 120 overweight volunteers. Those following the Atkins diet lost twice as much weight in 24 weeks but read the small print. Specifically, adverse effects occurred more frequently in the low-carbohydrate diet group than in the low-fat diet group, including constipation (68% vs. 35%; P < p =" 0.03)," p =" 0.02)," p =" 0.01)," p =" 0.006)." style="font-style: italic;">Annals of Internal Medicine 2004; 140: 778), two persons on the low carbohydrate diet died, and a third was hospitalised. No such adverse events were recorded in those following the high carbohydrate diet.
- There might have been some underlying health reasons for the ketoacidosis you mention.
The case of a woman who was hospitalised for life-threatening ketoacidosis was written up in The Lancet (Chen TY, Smith W, Rosenstock JL, Lessnau KD The Lancet – Vol. 367, Issue 9514, 18 March 2006, Page 958). The precipitating factor, whatever her individual vulnerability, was strict adherence to a low carbohydrate diet. Fortunately, most people don’t or can’t adhere strictly to the Atkins diet.
- No diet is really recommended for ill or pregnant people.
Pregnant women have to eat and the diet they eat affects their baby’s development. We use the word ‘diet’ in the sense of ‘eating plan’ (as defined by most dictionaries), not restricted energy intake. We agree that it’s not a good idea to restrict energy intake during pregnancy (one reason being the adverse effect of ketones on fetal development). But it’s vitally important that women eat a healthy diet throughout their pregnancy and throughout their reproductive years – because not every pregnancy is planned. A low GI diet fits the bill perfectly, a low carbohydrate diet doesn’t (and you appear to agree). If a diet’s not good for a developing fetus, why would it be good for anyone else?
- It is not true that consuming bad fats is unavoidable. You can and should avoid them and stay within Atkins.
If carbohydrates occupy only 10% of your energy intake (i.e. you eat about 50 grams of carbohydrates per day), then the other 90% of energy must come from a mix of protein and fat. The upper limit on protein intake by humans is around 40% of their calories (kilojoules) because of limits on the liver’s capacity to produce urea. By a process of deduction, that means more than 50% (and more often 60%) of energy comes from fat. Even if you ate a perfectly healthy balanced diet with a P:M:S: ratio of 1:1:1 (polyunsaturated, monounsaturated, saturated fat), you’d be consuming about 20% of your calories as saturated fat. The recommendation is less than 10%.
- I love carbs, I could be happy with a GI diet, and I will resort to it as soon as I reach my goal weight, but losing weight with GI diets is complicated because as soon as you surpass the level of carbs you can consume, you stop losing weight and start gaining.
That was the claim Atkins made but he had no scientific evidence to back that. To our knowledge, there’s still no evidence. Indeed, recent studies suggest that people find it very hard to stick to a diet with so little carbohydrate (too much discipline is needed) and eventually re-gain the weight they lost. Is there any point in losing weight and then re-gaining it? Wouldn’t it be better to align food habits with something that’s not only healthy, helps you lose weight and keep it off for good?
- As soon as I can start incorporating more carbs into my diet, they will be of the low glycemic load kind.
That’s good. Why not cut to the chase early?
- There should really be no quarrel between low glycemic and Atkins because they are fundamentally the same. The diets you should be strongly opposing are the low caloric and the low fat diets.
No, that’s incorrect. Atkins wants to ditch carbs. Low GI diets can be moderately or even very high in carbs, but of the low GI kind. If Atkins had known what we know now, he would have seen ways to lower insulin levels without cutting the carbs. He recognised that high insulin levels interfered with weight control, but he did not have sufficient knowledge to work out the best way to lower insulin. Remember he had no training in nutrition.
- The truth is that Atkins works. Once you get to your equilibrium level, then you can do low GL and stay in a narrow weight band.
Yes, we agree that Atkins works in the short term. But not the long term. So what’s the point in following such a diet?
‘There is no apparent metabolic advantage associated with ketosis during dieting’ report researchers from the Department of Nutrition, Arizona State University, Inflammation Research Foundation, Marblehead and Conscious Cuisine, Scottsdale in the May issue of the American Journal of Clinical Nutrition. In summarising their findings, Prof. Carol Johnson says: ‘In the current study, the ketogenic low-carb diet did not offer any significant metabolic advantage over the nonketogenic low-carb diet. Both diets were effective at reducing total body mass and insulin resistance, but, because blood ketones were directly related to LDL-cholesterol concentrations and because inflammatory risk was elevated with adherence to the ketogenic diet, severe restrictions in dietary carbohydrate are not warranted. Furthermore, the nonketogenic low-carb diet was associated with feelings of high energy and a more favorable mood profile than was the ketogenic low-carb diet.’ They recommend anyone wanting to follow a low-carb diet to choose low-fat meats and dairy products, and eat 8–9 servings of fruit and vegetables and 100–125 grams of carbohydrate a day.