Some people are under the impression that a high dietary protein diet will help with weight loss regardless of how many calories are eaten, but this is not really the case. You need the right amount for your lifestyle. Too much protein may hamper your ability to stop prediabetes unless you put it to good use making muscle with some resistance exercise.
A recent study published in the Journal of the American Medical Association (January 2012) shows that this is not the case, but there is still an important role for adequate protein in your diet.
Researchers set out to evaluate the effects on weight gain from eating low, normal, or high amounts of protein. They also looked at how these different protein amounts affected the ability to burn calories, and overall body composition. They found that eating too much food promotes fat gain regardless of how much protein you eat along with it, but different macronutrient ratios can impact the quality of your body composition.
The study used 25 patients — 16 males, 9 females — ages 18 to 35 years with a body mass index (BMI) between 19 and 30 who lived in the researcher’s clinic for the 8 week duration of the study.
After eating a weight-stabilizing diet to get everyone’s metabolism roughly on the same page, the people used for the study were randomly assigned to diets consisting of 5%, 15%, or 25% calories from protein.
During this second phase, the patients overate for eight weeks, increasing their overall calories by about 40%, or an additional 954 calories per day. All three diets included the same amount of carbohydrates, and fat made up the difference in the added calories.
All patients gained weight, but those in the low-protein group gained less than those who ate normal or high levels of protein (about 7 lbs. versus 13 lbs. and 14 lbs., respectively). It is interesting that the normal and high protein weight gain did not differ by much.
However, those in the low-protein group gained less lean body mass than those in the normal or high protein groups (about 1.5 lbs versus 6 lbs and 7 lbs). The added lean body mass mostly accounted for the differences in weight gain.
The researchers report that the overall increase in fat mass was similar between the three groups, rising about 7.7 lbs from their baseline.
More protein equals more calories so it is not that surprising that the study results showed that all patients gained weight, and that those in the low-protein group gained less than those who ate normal or high levels of protein. However they all had a similar increase in fat mass when they overate by about 1,000 calories a day, but the low-protein group did not gain the overall metabolic benefit of increased muscle development.
In my opinion, the low-protein dieters came out the worst overall. Yes, they weighed less, but had roughly the same level of body fat without the added lean muscle mass. Muscle tissue facilitates a healthy metabolism. The low-protein dieters gained less weight overall, but the weight they gained was mostly body fat. Excess body fat is inflammation producing and is related to metabolic syndrome and other health problems.
The solution is to eat sufficient protein for your body’s metabolism, muscle maintenance and growth while not having excess protein being converted to fat. The subject of how much protein is the right amount has been a topic of much discussion.
By the way, the researchers also found that the ability of people in the study to burn calories while resting, as well as their overall ability to burn calories, went up among those who had normal- or high- protein diets, but it didn’t change in the people that ate low-protein. This is apparently due to protein using more energy to digest and metabolize as well as the fact that the higher protein people put on more muscle mass–This is part the reason why some believe protein can essentially be eaten with impunity and have a weight loss effect. Not true. Just like carbohydrates and fat, there is an appropriate amount of protein macronutrients for a proper diet. These amounts will vary based on the state of a person’s metabolic health and activity level.
Just like finding the right balance of carbohydrates for your daily consumption, you have to find the right amount of protein for your genetics, body composition, activity level, and health. A rough starting guide for carbohydrates is about 120 grams/day and for protein, 0.4-0.5 grams/lb body weight. Talk to a healthcare professional with an interest in this area and stay in tune to Nutrientology for more on this topic.