Low-carb diets OK; no-carb diets unhealthy
April 12, 2009
Last week, in Part 1 of Nutritional (In)correctness, I shared with you some of the myths regarding saturated fat and cholesterol, as well as my general dislike for the USDA’s MyPyramid guidelines.
This time the topic is low-carb diets: Atkins, Protein Power, South Beach Diet and the TNT Diet are all popular examples. Once again, I cannot wait to hear academicians, registered dietitians and nutritionists out there tell me how wrong I am. After all, I’m just an undergraduate student.
(Go to www.washburnreview.org to partake in the ongoing discussion in the comments section).
Myth 4: Low-carb diets are dangerous and complete BS.
First, a quick overview: The body has two main ‘reserves’ of energy. We have stored carbohydrates in our muscles, known as glycogen, and then we have body fat. Our bodies love body fat because it’s an efficient way to store energy in case we ever run out of food, and not only can it hold a lot of calories, it can also make new fat cells (get fatter) if it needs to. Remember, our bodies are wired to survive and reproduce, having washboard abs or “toned” legs is the least of its concerns. Our bodies hate us … sorta.
Glycogen storage occurs in the liver and muscles, the more muscle you have, the more carbohydrates you can eat and the more glycogen you can store. At any time, the body runs on a mixture of both glycogen and body fat, but a full glycogen tank tells the body to use carbohydrates for energy instead of the stored fat. And not only does that blunt fat oxidation, but also, if your glycogen levels are topped, the excess carbohydrates will “spill over,” leaving your body with no choice but to turn that excess into fat and store it.
I’ll admit that’s a very gross overview of the physiology behind it (I’m leaving several processes and hormones aside), but hopefully you get the message.
Unless you are a highly trained athlete burning a ton of calories a day, for most healthy people, low-carb diets are a solid fat loss option. It’s important to clarify that a low carb diet DOES NOT mean zero carbs, even eating as many as 100 grams of carbs a day or 20 percent of total calories (in a 2000-cal diet) can still provide tremendous health benefits according to the medical literature.
What helps endurance athletes perform at their peak has nothing to do with helping the average individual trying to lose fat. Sure, you need to reduce total calorie intake to lose fat, but how about cutting down on carbohydrates instead of fat and/or protein.
USA Today recently published a list of the top selling books in the last 15 years (that’s a lot of books). Out of the top 150, nine were nutrition/diet books and seven were about low-carb plans. I would certainly not label BS a diet theory popular enough to reach such numbers. (USA TODAY’s list is based on sales at 4,700 chain, independent, discount and online booksellers, and combines fiction, non-fiction, hardcover, paperback or other categories on a single list.)
Never forget, the greatest diet is the easiest one you can stick to, and according to the medical research (and my experience) low-carb diets always have higher adherence rates than their carb-heavy counterparts.
Next week, on the last installment in this series, I’ll discuss protein and all the controversy surrounding it. I keep hearing “protein is bad for you,” “protein is bad for your kidneys,” “protein leads to bone loss.” But what does the science say? Can too much protein really kill you?