So I just saw a blurb about this study from this month’s American Journal of Clinical Nutrition:
Design: Men (n = 16) aged 22 ± 1 y (mean ± SE) were randomly assigned to 5 d of a high-fat, low-carbohydrate diet containing 75 ± 1% of calorie intake through fat consumption or to an isocaloric standard diet providing 23 ± 1% of calorie intake as fat. In a crossover design, subjects undertook the alternate diet after a 2-wk washout period, with results compared after the diet periods. …
Results: Compared with the standard diet, subjects who consumed the high-fat, low-carbohydrate diet had 44% higher plasma free fatty acids (P < 0.05), 9% lower cardiac PCr/ATP (P < 0.01), and no change in cardiac function. Cognitive tests showed impaired attention (P < 0.01), speed (P < 0.001), and mood (P < 0.01) after the high-fat, low-carbohydrate diet.
Conclusion: Raising plasma free fatty acids decreased myocardial PCr/ATP and reduced cognition, which suggests that a high-fat diet is detrimental to heart and brain in healthy subjects.
Really Oxford researchers? I guess they’ve never heard of induction flu, the temporary “mental fuzziness, fog and fatigue” many folks experience when initially going low-carb.
Here’s my lay take: if you want to test the response to a high fat diet, let the subjects acclimate to it first!