Drinking a protein shake as part of your post-workout routine might be sabotaging your efforts to lose weight. New research suggests timing is everything when it comes to using protein supplements.

Protein powders or protein bars can be useful if you are trying to gain, lose or manage your weight or improve your body composition, depending on how you use them in your eating plan.

The calories in protein shakes and bars do not come free.

Looking at the results of several past studies, researchers at Purdue University found that using protein supplements did help increase lean body mass, but when they are used can make a difference in body composition.

Eating or drinking a protein supplement with a meal helped people maintain their weight and decrease their fat mass. But when people took the supplements between meals they tended to gain weight. So if you are trying to gain weight, using protein supplements between meals makes perfect sense.

But when weight gain is not the goal, people may need to adjust how much they eat at a meal in order not to overdo the calories, according to Wayne Campbell, senior author of the study.

The problem is that when protein supplements are used between meals as snacks, the calories they provide may be forgotten at meal times. The result is a higher calorie intake for the day, which makes managing weight more difficult. Taking a supplement with a meal and making the calories part of that meal can be a good way to keep weight and body composition under control.

The calories in protein shakes and bars do not come free. If you use protein supplements regularly, be sure to count the calories in them as part of your total calorie intake for the day to avoid an unhappy surprise the next time you get on a scale.

The study is published in Nutrition Reviews.