Does Fruit Make You Fat?

Column by John Parrillo at Parrillo Performance.

Why do you exclude fruit and fruit juices from your Nutrition Program?

I am frequently asked to explain why fruit and fruit juices are not included in my Nutrition Program. The answer has to do with a little-understood simple sugar found in fruit: fructose. Fructose came into favor years ago because of its low glycemic index. Unlike other simple sugars, it triggers neither a surge in insulin nor acorresponding drop in blood sugar an hour or more after eating it. But there’s more to the fructose story. After you work out, your body moves from an energy-using mode (catabolism) to an energy-storing and rebuilding mode (anabolism). During the transition, dietary carbohydrate is broken down into glucose and fructose to be used for “glycogenesis,” the manufacture of glycogen to restock the muscles and liver. Fructose is used primarily to restore liver glycogen; it’s really not a good re-supplier of muscle glycogen. Glucose, on the other hand, bypasses the liver and is carried by the bloodstream straight to the muscles you just worked, where the glycogen-making process begins.

Any muscle emptied of glycogen due to exercise is first on the list to get its quota of glucose. Clearly, one of the keys to effectively restoring glycogen is the type of carbohydrate you eat. Natural, complex carbohydrates such as potatoes, yams, whole grains, corn, legumes or maltodextrin-based drinks like our Pro-CarbTM Formula do a better job at this than simple sugars do. In one study, a diet high in starchy carbohydrates restocked more glycogen in the muscles 48 hours after exercise than simple sugars did. If you eat simple sugars like fructose, you’re not going to be able to store as much glycogen. What implications does this have for you as an athlete or bodybuilder? First, you won’t be able to train as hard or as long during your next workout because you will be glycogen-deficient.

Second, you’ll notice less of a pump while working out, also due to lower glycogen stores in the muscle. If you can’t get a good pump, it’s difficult to fully stretch the fascia tissue surrounding the muscle when you stretch between sets. This limits your growth potential. Third, fructose is easily converted to body fat. Because of fructose’s molecular structure, the liver readily converts it into a long-chain triglyceride (a fat). Therefore, a majority of the fruit you eat can end up as body fat on your physique. People on our program notice incredible differences when they eliminate fruits and juices from their diets. If you want to get leaner and more muscular — and build your recuperative powers by restocking glycogen more efficiently — avoid fruit altogether and choose starchy and fibrous carbohydrates instead, as our Nutrition Manual recommends.

John Parrillo
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