So what are triglycerides? Well, they are fats that the body uses for energy and everybody needs them. But, having too much of them can be detrimental to the body and lead to serious and long term health consequences. High triglycerides are often the result of a lack of physical activity and a poor diet, meaning that reversing these risk factors can have a dramatic impact on keeping the body healthy and thereby reducing the risk of cardiovascular illness and stroke. In fact, those wondering what are triglycerides can sort of consider them one way to measure overall health in terms of diet and exercise levels. Higher levels can indicate a diet that is high in refined and fatty foods or a lack of exercise, and be a means to understand important lifestyle changes that can be made in order to promote better overall health and a reduced risk of disease.
What we’re finding out is that exercise and fasting can raise LDL a lot in lean, healthy people. Whereas these same factors will tend to lower LDL (at least at first) in high-risk individuals. Recently Dave Feldman has shown that the more fat a lean, healthy person eats before a cholesterol test, the lower their LDL will be.
From this it seems that LDL cholesterol levels in the past have been based on populations of middling fitness, eating conventional diets, and correlations drawn from them may not be accurate at all for anyone outside this demographic, for example the low carb, crossfit generation. TG and HDL, meanwhile, continue to behave much as expected – sugar will increase TG and (eventually) lower HDL in anyone.