Low-fat, high-carbohydrate diets had the official U.S. seal of approval since 1979. Low-carbohydrate diets, such as the Atkins diet,
were wildly popular in the 1970s and again during the past five years. Well-controlled studies show that people can lose weight on the
Atkins (restricts carbohydrate), Ornish (low-fat), Weight Watchers (low-calorie) and Zone (nutrient intake balanced) diets, but which
one is best?
A study of 160 people by researchers from Tufts University New England Medical Center showed no difference in weight loss or changes
in cardiovascular disease risk factors such as blood pressure, BMI, cholesterol, LDL, HDL, or C-reactive protein between groups assigned
to each diet plan for a year. Each of the diets helped people lose a modest amount of weight after one year (four to seven pounds).
Adherence to the diet was equally poor in each of the groups. The study showed that each of the diets was equally effective at 12 months
if you stick to the diet plan so find the one you can stay with.
The Science Behind Low-Carb Diets
Low-carbohydrate, high-protein diets are not as popular as they were last year, even though the science supporting them has increased. Low-carb
diets force the body to use fats instead of carbohydrates as fuel. The body prefers to use carbohydrates as fuel and save fats for emergencies.
It's easy to store fat, but very difficult to lose it. High-sugar diets stimulate insulin in response to high blood sugar levels. Insulin is
essential for transporting sugar into the cells, but it also promotes fat storage. Low-carb diets keep insulin release to a minimum, which
increases fat use for energy and in turn, promotes fat loss. Drs. Jeff Volek and Matthew Sharman summarized nearly 10 years of research on
low-carbohydrate diets. Compared to traditional low-fat diets, lowcarb diets consistently caused greater improvements in fat loss, blood fats and
insulin resistance. More research is needed to assess the long-term effects of these diets.
Weight Loss Similar in Low and High-Carb Dieters
Most studies show that people lose more weight in six months on low-carbohydrate (LC) than low-fat diets (LF). Critics say people consume fewer
calories on LC diets, which accounts for their success. Researchers from the Albert Einstein College of Medicine found that subjects lost the same
amount of weight on low-carb and low-fat diets when they consumed the same number of calories and protein. The study showed that people lose more
weight on low-carbohydrate diets because they eat less.
Protein and ketones (produced during low-carb diets) suppress appetite and decrease caloric intake. This study examined only four subjects, so the
results are just preliminary.