We read with interest the recent article reporting weight and lipid changes after a “modified low-carbohydrate (MLC) diet,” which theoretically combines the benefits of carbohydrate restriction and saturated fat restriction.1 In several randomized controlled trials of the ad libitum low-carbohydrate ketogenic diet (LCKD), which has no saturated fat restriction, weight loss and elevation in high-density lipoprotein cholesterol (HDL-C) level are recurring findings.2- 7 This is in contrast to the lack of elevation in HDL-C levels in the MLC diet (Table). This result is perhaps not surprising because saturated fat raises HDL-C level more than unsaturated fats.8 A recent outcome study has found that higher saturated fat intake is associated with less progression of coronary atherosclerosis.9 So, the combination of carbohydrate restriction with saturated fat restriction may make intuitive, but not scientific, sense.
Westman EC, Yancy WS, Vernon MC. Is a Low-Carb, Low-Fat Diet Optimal?. Arch Intern Med. 2005;165(9):1071-1072. doi:10.1001/archinte.165.9.1071-b