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:
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.
What these studies find is that overweight kids with high blood pressure and cholesterol profiles associated with high carbohydrate consumption (“low HDL” is a bad thing because HDL is considered the ‘good cholesterol’) tend to have heart disease as adults.
Keep in mind, fat consumption (saturated and unsaturated) raises HDL (the good cholesterol).
We are talking about sick kids turning into sick adults. And they are probably eating too much carbohydrate.
It used to be believed that these people developed obesity, heart disease, high blood pressure, and diabetes because they ate too much fat. But many groups eat lots of fat and didn’t have high rates of chronic diseases, so the hypothesis was revised to suggest that these kids were eating too much saturated fat. And maybe not exercising enough. Further evidence has done that hypothesis no favors, and now the concern is that maybe these folks are eating too much carbohydrate (yes, the thing they were told to eat MORE of all along).
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 heavier or fatter.
Rachel Brown was a member of both research teams and would go on to become an important researcher on the subject of Low Energy Availability (LEA) in athletes, a precursor to the female athlete triad, a dangerous syndrome caused by athletes undereating compared to the demands of exercise and normal physiological needs.
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.