Search engine giant Google recently revealed the most frequently searched-for diets of 2013. Leading the list: Low-carb Paleo and ketogenic diets. In an exclusive Dec. 23 interview, physiology and nutritional biochemistry scientist William Lagakos, Ph.D., explained to me how and why diets low in carbohydrates work for weight loss.
When it comes to shedding pounds, studies show that when you compare low carbohydrate diets with high carbohydrate diets, "almost always show more weight loss in those assigned to the low carbohydrate diet," says Lagakos, author of "The poor, misunderstood calorie: calories proper" (click for details).
And how does the quality versus quantity of carbohydrates impact weight loss?
"Studies comparing high vs. low glycemic index diets (but same quantity of carbohydrates) do tend to show improved markers of health associated with healthier, low GI carbohydrates, although the data on weight loss are not very compelling," noted Lagakos.
Thus, when it comes to weight loss alone, "carbohydrate quantity might matter more than quality," he said.
For example, if you compare the results of 200 grams of carbohydrates consisting of sugar and refined, processed foods such as white bread versus 225 grams of "healthy" carbohydrates such as whole wheat pasta and brown rice, those so-called healthy carbs will not help when it comes to slimming down on a low carb diet.
Although we sometimes think of all low carbohydrate diets as the same, they aren't. And one category of low carb dieting that has become popular is perhaps the most misunderstood: Ketogenic diets that are high in fat as well as high in protein.
"A ketogenic diet is a very low carbohydrate, high fat diet. It is characterized by having normal glucose levels and elevated ketones in the blood," explained Lagakos.
"Exactly how low in carbohydrate depends on a variety of factors, although it is probably in the ballpark of 20-50 grams per day. Higher if you’re more physically active or are in an energy deficit; lower if you’re sedentary or maintaining/gaining body weight," he said.
To maintain a state of ketosis and burn fat for energy, two elements are key: Energy deficit and carbohydrate restriction.
"And since there is generally a limit to the amount of protein one can eat in a day, the majority of the calories are dietary fat," noted Lagakos.
As far as what really works when it comes to weight loss?
"Scientifically speaking, most of the data suggest a low carbohydrate diet is very effective for weight loss. Exercise is also important because what we really care about is body composition, not necessarily body weight per se," stated Lagakos.
By exercising and eating a low carb diet, you can "promote nutrient partitioning, which is the selective loss of body fat while muscle mass is maintained or increased," he concluded.
For that reason, more athletes are opting for low carb Paleo-style diets, which provide them with a way to shed weight while maintaining or boosting muscle mass. Learn more about these diets work by clicking here.