Failure of LC/HF Diets to Suppress NEFA Release

Thanks to reader MM, I have procured a full text copy of the following study that I've discussed a bit previously:  Lack of suppression of circulating free fatty acids and hypercholesterolemia during weight loss on a high-fat, low-carbohydrate diet

A bullet pointed, sometimes paraphrased abstract/summary:

• This study compared a low carb (less than 20g/day, no fat content provided but "high fat") diet to a high carb diet (55% energy, 30% fat) 

• Fasting, 24 hour AUC (cumulative exposure) and time courses for metabolites were measured during weight loss.

• Subjects were healthy, obese adults (n = 32; 22 women, 10 men) - diabetics and those with a history of CVD were excluded.

• The study lasted six weeks. 

• A 24-h in-patient feeding study was performed at baseline and after 6 wk. Glucose, insulin, free fatty acids (FFAs), and triglycerides were measured hourly during meals, at regimented times. Remnant lipoprotein cholesterol was measured every 4 h.

• Results:

• Patients lost a similar amount of weight in both groups 

• There was no difference between groups on fasting triglycerides or on remnant lipoprotein cholesterol, which was the main outcome. 

• Fasting insulin decreased, and both fasting and 24-h FFAs  increased within the High Fat group. 

• Twenty-four-hour insulin decreased for both groups. 

• Fasting LDL cholesterol decreased in the High Carb group only.

• In both groups, the differences in fasting and 24-h FFAs at 6 wk were significantly correlated with the change in LDL cholesterol.

• Conclusions: Weight loss was similar between diets, but only the high-fat diet increased LDL-cholesterol concentrations. This effect was related to the lack of suppression of both fasting and 24-h FFAs.

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