There’s a to advocate a low-carbohydrate diet. The most calorie dense carbohydrates tend to come from grains. While the paleo crowd have arguments about the dangers of grains in terms of gluten and lectins, from a purely weight-loss point of view, grains are calorie-dense and nutrient poor. Removing dense carbohydrates from the diet (and depending on the approach can include fruits, potatoes and other starchy vegetables) certainly frees up a lot of calories that can be used to bulk up the meal – leafy vegetables and meats and fats.
There is also the argument against carbohydrates as outlined in by Gary Taubes : Outline here that looks at the health issues caused by spiking our blood sugar levels. Unfortunately this tends to fall by the wayside and the reason most people hear about low-carb diets is the weight-loss side – or more specifically fat loss.
This is where the debate gets more complicated over how far to cut back. Do you need to go to a ketogenic diet in order to get the advantage of low-carb? A new study suggests not:
In terms of weight and fat loss, at the end of 6 weeks both groups had lost roughly the same amount of weight (6.3kg for the ketogenic diet, and 7.2 kg for the non-ketogenic diet; this was not statistically significant). As well, the loss of body fat was the same (3.4 kg in the ketogenic diet and 5.5 kg in the non-ketogenic diet; again this was not statistically different even if the non-ketogenic diet seems to have lost ~4 pounds more fat). There was no significant change in fat free mass for either diet.
You could argue that ketogenic diets make things simpler – but if you’ve ever looked on a message board as people discuss the merits of one or two grams of carbs, you might doubt that. However, I appreciate that the internet is the place for that kind of nerdery and you can get a false idea of its complexity based on people having fun with that kind of detail. Personally – I prefer eating some carbohydrates. I’ve adjusted enough that I think of bread, pasta and rice as cheating along with more standard cakes, chips etc. But I’m at a point where I don’t want to be not adding a zuccini to my stirfry because of the the carbs.
Hunger ratings improved for both diets with no difference between diets. An oft-heard claim is that ketogenic diets cause hunger blunting due to the presence of ketones or what have you; but this study does not support that. Given that protein is the most filling nutrient, the effect seems to be mediated by the increased protein content, not decreasing carbohydrates per se.
While I acknowledge the study was small and relatively short-lived, I found it interesting that there was no difference in perceived hunger. As someone who responds quite strongly to blood sugar level peaks, the moderating my hunger was one of the key reasons I started looking at cutting back my carbohydrates. I’ve of late been trying to push the fat content of my diet up, but now I’m wondering if I should be trying to push protein instead.