BAKERSFIELD, Calif. -- When it comes to choosing a diet, there are many strategies available. Should you try a high-protein diet? Maybe a low-fat regimen would be better.

Surprisingly, new research has suggested that the particulars of a diet may not matter at all.

Doctors from Brigham and Women's Hospital compared four types of diets that differed in their amounts of protein, fat and carbohydrates. Obese patients followed one of the four diets for two years.

Results showed that people lost about the same amount of weight -- 13 pounds -- no matter which diet they tried.

Risk factors for heart disease, such as cholesterol and blood sugar problems, improved in all the groups as well.

Those who stuck with their diets and attended counseling sessions were more likely to see big weight loss -- 22 pounds or more.

Experts said the study proves that the exact nutrients in a diet aren't important -- high or low protein, regular or low fat. They can all be effective if you limit calories and stick with the program.