Coronary risk factors measured in children and young adults are associated with the early development of coronary artery calcification. Increased body mass index measured during childhood and young adult life and increased blood pressure and decreased HDL cholesterol levels measured during young adult life are associated with the presence of coronary artery calcification in young adults.In plain language, sick kids become sick adults. Overweight kids with high blood pressure and bad cholesterol profiles tend to have heart disease as adults. How many of your swimmers are sedentary, overweight, and hypertensive? Also, fat consumption (saturated and unsaturated) raises HDL (the good cholesterol). If their problem were too much dietary fat, it is hard to understand how they could have low HDL. No studies find that healthy teenage athletes – even those who eat like Katie Ledecky or Michael Phelps – are more likely to develop heart disease as adults. In fact, studies find endurance athletes do well when placed on high fat diets (50% of total calories), that these diets ‘did not result in adverse changes to the plasma lipoprotein profiles‘ (meaning their cholesterol was fine), and did ‘not increase body weight or adiposity‘, which is a research-y way to say they didn’t get fat. The real danger for teenage athletes, especially endurance athletes and especially women, is Low Energy Availability (LEA) which has significant adverse health effects on athletes (and not insignificantly, hurts performance too). One of the better ways to combat LEA: eat more fat. Diets at the upper end of what is recommended by the American College of Sports Medicine – 30% – are associated with top performance and reduction in symptoms of LEA.
But wait! Don’t the origins of cardiovascular disease begin at an early age and progress into adulthood, and isn’t elevated dietary fat intake associated with the development of cardiovascular disease? Let’s take a look at some typical research in this field: