Lose the Carbophobia!

In the world of sports nutrition, I have encountered several different mentalities with regards to carbohydrates. High GI carbs post-workout, no carbs before bed, avoid fructose-rich fruit, carbs shouldn't be mixed with fatty meals, and my personal favorite, low-carb dieting for weight loss. All of these ideas have modest logic however little scientific evidence has supported these claims. I will briefly go over these common misconceptions and, in my next post, place special emphasis on low-carb dieting. Please email me with questions and comments. Enjoy!

Brief Breakdown of Carbohydrates
Carbohydrates are our main energy source and provide 4 Calories per gram. However, not all carbohydrates are the same. They can be classified into two categories: simple and complex. Simple carbs are mono and disaccharides and are found in table sugar, fruits, milk, honey, and prepared sugars such as high-fructose corn syrup (HFCS). Complex sugars, such as starch in plants and glycogen in muscles, are long chains of simple sugars that breakdown to release sugars. Sources include potatoes, brans, wholegrain flours, breads, and pastas, vegetables, and nuts. Another classification of carbohydrates is the Glycemic Index (GI) based on how slow or fast 50 grams (200 Calories) of that sugar will increase blood glucose levels. This system was initially used by diabetics to help control their blood glucose but many athletes have found its individual ranking of foods as a potential advantage to increase performance. In theory, low GI ranked foods consumed pre-workout help endurance athletes by providing constant energy through the slow release of glucose whereas high GI foods consumed immediately post-workout rapidly refuel depleted muscles, which brings me to my first rebuttal.

High GI Carbohydrates Post-workout
Some athletes feel that immediately after a workout it is necessary to spike insulin levels to create an anticatabolic response and re-synthesize glycogen. Unfortunately, there are flaws in this logic and research has shown that spiking insulin immediately post-workout provides no benefit. Before I continue, exists one exception for the athletes who undergo two or more exhaustive workouts within 6-8 hours of each other, however this is not the majority of us and this information may not apply to them. For the rest of us, the Glycemic Index shouldn't be stressed for several reasons. First, it is very sensitive to portion size, origin, and preparation of the food. Second, glycemic response varies greatly in each of us on a day-to-day basis. And third, well-trained muscles readily take up carbohydrates from the bloodstream (meaning insulin spikes don't necessarily occur in athletes).

No Carbohydrates After 9PM
One persistent theme I have encountered is that carbohydrates at night or before bed can lead to weight gain. This is silly in my opinion as the real culprit of weight gain is simply excess calories, not carbohydrates before bed. This is especially the case for those who train in the evenings whose muscles could properly recover from the post-workout carbs. One thing to keep in mind is that much more importantly than the timing of when to eat your carbohydrates, is actually meeting your estimated daily needs (see first post).

Avoid Fructose-Rich Fruit
I continue to be amazed when I hear people say to avoid fruit because of its fructose content. In this popular youtube video Dr. Lustig of UCSF goes as far as to associate fructose with poison. On a sidenote, if you watch this long video, I encourage you not to make any grand realizations. Nonetheless, fructose has been under a lot of scrutiny and since fruit contains relatively high amounts of fructose (about 6-7 grams), many bodybuilders see fit to avoid it. This is because fructose causes minimal insulin secretion and can potentially lead to fat synthesis in the liver. The problem here is that very rarely is fructose alone in foods. For example, all of that HFCS in our food contains almost equal ratios of glucose to fructose. Also, In many fruits, there is about a 1:1 fructose to glucose ratio (sometimes as high as 1:2). Bottom line, these food items can elicit an insulin response. As for increased fat synthesis, this has been evidenced in high intake of 50+ grams. This would mean 9 servings of fruit. Before you say that isn't so much, especially when combined with all the HFCS in our foods, fruit also contains almost as much fiber which, as Dr. Lustig claims, neutralizes the fructose. Now I'm not saying eat all the fructose you can, I'm merely proposing that fructose is dose-dependent. Within moderation, I would not overly stress it. Especially since fruit also contains vitamins, minerals, fiber, and phytochemicals important for muscle nourishment. *Note that these are the substances that soft drinks lack

No Carbohydrates With Fat
I feel like this mentality is related to the misguided idea that carbs are fattening. Again, excess calories are fattening and it is easy to forget about the butter on bread, mayonnaise in a sandwich, and oil in pasta that contribute a lot of fat calories to those carbs. In the bodybuilding world, this theory is likely more related to the idea that fat circulating in the bloodstream should not be available when insulin is raised because it will lead to creation of more adipocytes (fat cells). Insulin is an anabolic hormone but in reality, the type of fat (unsaturated or saturated) will make a significant difference in the insulin response of the carbs. For example, the insulin response to carbs ingested with unsaturated fats is likely to be unaffected whereas that of carbs ingested with saturated fats is raised. Nonetheless, these types of fat can lead to increased Triglyceride (TG) storage even if insulin isn't available. My take home point here is that fat storage is dependent upon multiple variables and not simply with insulin alone. This type of separation in meals could be difficult to follow and isn't shown to produce any weight-loss benefits. On the contrary, evidence has shown, eating a diet consisting of mixed substrate meals within your caloric recommendations is more beneficial.