Choosing a diet can be difficult. With so many competing options, how can you decide which one will be best?
A 2008 study in the New England Journal of Medicine suggests that you should choose whichever one you prefer!
The low-fat diet was based on guidelines from the American Heart Association. It restricted calories (1500 calories a day for women and 1800 for men) with 30 percent of calories from fat and 10 percent of calories from saturated fat. Cholesterol was limited to 300 milligrams a day, and these dieters were advised to eat plenty of fruits, vegetables and grains.
The Mediterranean diet replaced red meat with fish and poultry, restricted calories (1500 calories a day for women and 1800 for men) and allowed more fat. Up to 35 percent of calories from fat were permitted, and these dieters were asked to consume olive oil and nuts.
The low-carb diet was styled after the Atkins diet. It didn’t set any limits on calories or fat, but it restricted carbs to 20 grams a day for the first 2 months. Low-carb dieters were later allowed to gradually increase their carb intake to 120 grams a day.
The Weight Loss
Each of 332 moderately-obese people—most of them men, with an average age of 52—was randomly assigned to a diet for the duration of the two-year-long study. All of the groups lost weight, but the Mediterranean and low-carb groups lost more than the low-fat group did.
The low-fat group lost an average of 2.9 kilograms, or 6.4 pounds, and 1.1 inches from the waistline.
The Mediterranean group lost an average of 4.4 kilograms, or 9.7 pounds, and 1.4 inches from the waistline.The low-carb group lost an average of 4.7 kilos, or 10.4 pounds, and 1.5 inches from the waistline.
Who Was Healthier?
The study also measured other indicators of good health, like cholesterol and blood pressure.
All three groups lowered their blood pressure by about the same amount.
Good cholesterol increased in all groups, with the low-carb group showing the greatest increase. The low-carb group also had the greatest decrease in triglycerides. Bad cholesterol didn’t change significantly in any of the groups.
The Mediterranean diet changed glucose and insulin levels for the better, possibly because of the mono-unsaturated fats often found in that diet.
Choosing a Diet
Low-carb and Mediterranean diets are just as healthy and effective as low-fat diets. If you’ve found that you can’t make yourself reduce your calorie intake, restricting your carbohydrate intake but eating as many calories as you like might be the best solution. Because the study showed no significant differences in results, it’s safe to say that you can choose whichever diet you prefer.