In the study, ninety-three subjects were randomized into two groups:
- The high-carbohydrate dieters consuming a calorie restricted diet with 46% carbohydrate, 24% protein and 30% fat. Women consumed approximately 1429-calories each day, or 164g carbohydrate, 48g fat and 86g protein. Men consumed approximately 1667-calories each day, or 192g carbohydrate, 56g fat and 100g protein.
- The low-carbohydrate dieters consuming a calorie restricted diet with approximately 4% carbohydrate, 35% protein and 61% fat. Women consume approximately the same calories as above (there was no statistically significant difference for calories consumed in the study), or 15g carbohydrate, 97g fat and 125g protein. Men consumed approximately the same calories as above, or 17g carbohydrate, 113g fat and 146g protein.
Throughout the study, over the course of eight weeks, foods were provided to subjects and every two-weeks weight was taken and mood measured. Compliance by those following the low-carb diet was verified by measuring urinary ketone levels.
Both diets resulted in statistically significant weight loss.
The low-carbohydrate diet resulted in a statistically significant greater weight loss over the eight-week period than the high-carbohydrate diet, with low-carb dieters losing an average of 7.8kg (17.2-pounds) compared to 6.4kg (14.1-pounds) in the intent-to-treat analysis (p=0.04).
Both groups showed improvements in psychological well-being (p=0.01 for time) and there was no significant difference in working memory. The researchers noted "[t]here was some evidence for a smaller improvement in cognitive functioning with the LCHF diet with respect to speed of processing, but further studies are required to determine the replicability of this finding."
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