Publisher: The Ohio State University



Series/Report no.: The Ohio State University. School of Physical Activity and Educational Services Honors Theses; 2013



Abstract:

Background: The Paleolithic (Paleo) diet is one modeled after the perceived food consumption of early human ancestors of the Paleolithic Era, consisting of mainly meat, fish, fruit, vegetables, eggs, and nuts. The purpose of this study was to examine the effects of a Paleo diet on blood lipids, including high-density lipoprotein (HDL), low-density lipoprotein (LDL), non-HDL cholesterol, triglycerides (TG), total cholesterol (TC), and the ratio between TC and HDL (TC/HDL) in a healthy population. Methods: Subjects of both genders (23 males, 20 females) with no history of diabetes, heart disease, dyslipidemia, or other metabolic disease were asked to eat an ad libitum Paleo diet for 10 weeks. Throughout the intervention, subjects participated in a CrossFit-based, high-intensity circuit training exercise program. Prior to the intervention, body weight, body fat percentage (BF%), maximal oxygen consumption (VO2max), TC, TG, HDL, and LDL were measured. These measurements were repeated following 10 weeks of a Paleo diet. Results: As a whole, there was a significant increase in non-HDL (107.1 ± 6.0 mg/dL to 120.2 ± 6.5 mg/dL; P < 0.01), LDL (93.1 ± 5.4 mg/dL to 105.6 ± 6.1 mg/dL; P < 0.01), TC/HDL (3.0 ± 0.2 to 3.3 ± 0.2; P < 0.05), and TC (168.8 ± 5.4 mg/dL to 178.9 ± 6.6 mg/dL; P < 0.05) in healthy subjects following a Paleo diet. When stratified into groups based on initial blood lipid levels, deleterious changes were found in those with optimal HDL (82.1 ± 3.2 mg/dL to 68.6 ± 4.8 mg/dL; P < 0.05), non-HDL (86.6 ± 3.9 mg/dL to 101.4 ± 4.8 mg/dL; P < 0.01), TC (157.2 ± 0.7 to 168.2 ± 0.9 mg/dL; P < 0.05), TC/HDL (2.5 ± 0.1 to 2.7 ± 0.1; P < 0.05), and LDL (69.1 ± 3.1 mg/dL to 83.5 ± 4.1 mg/dL; P < 0.01), whereas those within sub-optimal stratifications showed no significant changes. Subjects also decreased body weight (177.6 ± 5.8 lbs to 170.6 ± 5.3 lbs; P < 0.001) and BF% (24.3 ± 1.2% to 20.7 ± 1.2%; P < 0.05), while increasing VO2max (3.18 ± 0.14 L/min to 3.46 ± 0.15 L/min; P < 0.001). Conclusions: Our results demonstrate that an ad libitum Paleo diet intervention is associated with deleterious changes to blood lipids in healthy subjects, despite concurrent improvements in body composition and cardiorespiratory fitness. Future research should focus on determining recommendations that embrace the positive aspects of the Paleo diet, while minimizing any deleterious impact on blood lipids in a healthy population.