Accumulation of body fat is affected, in part, by the amount and types of food we consume. Reducing intake of saturated fats and increasing the quantity of whole grains, vegetables, lean protein, and fish in the diet can reduce one’s risk of fat accumulation (1).
Compounds and nutrients in the diet can have a direct influence on health. There is also considerable variation in individual responses to a given diet and one’s response to a particular diet may be influenced by their genetic makeup (1). An individual’s susceptibility to weight gain in response to a diet high in saturated fats may be affected by their genetics and is termed fat sensitivity.
But what does fat sensitivity mean? Some genetic variants that may be involved in fat metabolism are those that produce proteins, known as apolipoproteins, that carries fats out of tissues into the blood to be used elsewhere or degraded by the liver. Genetic variations that affect the way these proteins function can impose a negative effect on fat metabolism and the body’s response immediately following a meal high in saturated fat (1).
As with many genetic variations that are associated with certain health outcomes or traits, the genetic link is not so straightforward. One of the most well-studied variations that has been linked to sensitivity to fat intake is that of the gene involved in the production of apolipoprotein A2 (APOA2). APOA2 is a protein found in high-density lipoproteins (HDL; also called the “good” cholesterol). The way that genetic variations in HDLs affect fat metabolism, however, is largely unknown (2). Although the mechanism is unclear, several high-quality studies have identified in some individuals a specific genetic variation in the APOA2 gene that results in an increased susceptibility to weight gain from a diet high in saturated fat intake (3).
So what can you do with knowledge about your genetic profile and how it might affect your sensitivity to fat intake? Consultation with a health professional to help you understand, interpret, and apply knowledge about the impact of your genetics on your body’s response to dietary intake is essential. Regardless of what genetic variations you might possess, unsaturated fats, such as those found in vegetable oils, avocados, and nuts, are an important part of any diet and provide a significant portion of an athlete’s energy during endurance exercise. Limiting your intake of saturated fats is strongly recommended to maintain healthy cholesterol levels and body composition. And there is evidence to suggest the actual amount of saturated fats is less important than the ratio of saturated to unsaturated fats (4).
(1) Curti et al., 2011. “Studies of Gene Variants Related to Inflammation, Oxidative Stress, Dyslipidemia, and Obesity: Implications for a Nutrigenetic Approach.,” Journal of Obesity 2011:497401.
(2) Smith et al., 2013. “Apolipoprotein A2 Polymorphism Interacts with Intakes of Dairy Foods to Influence Body Weight in 2 U.S. Populations.,” The Journal of Nutrition 143(12):1865–71.
(3) Camp & Trujillo, 2014. “Position of the Academy of Nutrition and Dietetics: Nutritional Genomics,” Journal of the Academy of Nutrition and Dietetics 114(2):299–312.
(4) Müller et al., 2003. “The Serum LDL/HDL Cholesterol Ratio Is Influenced More Favorably by Exchanging Saturated with Unsaturated Fat Than by Reducing Saturated Fat in the Diet of Women.,” The Journal of Nutrition 133(1):78–83.