Effect of a Low-Carbohydrate Diet on Appetite, Blood Glucose Levels, and Insulin Resistance in Obese Patients with Type 2 Diabetes
(The full text is not supposed to be free, but through this link I was able to access it as a "patient", if it doesn't work for you, ask in the comments and I'll be glad to email you the PDF I saved)
Although this is a relatively short and small study, it demonstrates what many in the LC community are strangely averse to acknowledging -- that LC leads to a spontaneous caloric restriction in most low carbers. These folks restricted their caloric intake by an average of just over 1000 cal/day (median around 750). Here are the dietary differences:
Before: Carb intake ranged from 182g/day to a whopping 552g/day and averaged just over 300g/day.
After: Carb intake ranged in a ketogenic range of 14-32g and averaged 21g/day -- VLC
The difference, an average of around 280 g carb/day corresponds to 1120 calories.
What I found really interesting is the corresponding fat and protein intakes. I expected protein intake to increase dramatically, but average intake increased only 14g/day (looking at the difference column, these were the differences for each patient then averaged, so there were presumably participants that decreased their protein significantly (one by a fairly sizable 64g). Perhaps this was the person who was consuming that whopping 552g carbs at onset? In any case, as stated by Westman, et.al. in their LC Nutrition & Metabolism review,
Whereas instruction in an LCD does not mention calories, the restriction of dietary carbohydrate leads to a reduction in caloric intake from baseline. The ad libitum intake can vary from person to person, but, in many cases, the protein and fat intakes, in absolute terms, are not much higher than those of a typical American diet, because thetotal caloric intake is lower. As such, the LCD is not necessarily a high-protein diet or a high-fat diet.This was born out by this study. On average, the participants did not replace carbs with fat or protein to any great extent. So percentage-wise their diets were higher in protein and fat, but absolute consumption-wise, they were not raised significantly in either macronutrient.
Usual Diet: fat+protein accounted for 1934 cal, 28% protein/72% fat
LC Diet: fat+protein accounted for 2080 cal (only 150 cal combined increase), 29% protein/71% fat
Also, even in the short term, this study did NOT demonstrate any so-called metabolic advantage.