Leslie Beck on the weight-loss benefits of protein
Published Wednesday, August 17, 2011 7:50AM EDT
How does eating more protein help you lose weight?
A higher protein diet helps put the brakes on hunger, which can improve weight loss results by curbing calorie intake. In this new study women were assigned to a 1400 calorie diet. After six months, women in the protein group were consuming about 1370 calories per day; those on the higher carbohydrate diet, however, were eating about 1625 calories daily.
But protein is also very important for maintaining muscle mass when you cut calories. Women who diet are at greater risk of losing muscle mass and muscle strength, consequences that could undermine balance, mobility, overall strength and physical performance. Loss of muscle can even impact how well women perform everyday tasks like walking upstairs or getting up from a chair.
Research has shown that older adults who get more protein in their diet are less likely to lose muscle as they age. Yet, many women cut back on protein when trying to lose weight.
So how much protein should women eat if they want to lose weight? What about men?
Women who don't exercise need about 0.4 grams of protein per pound of body weight per day. So, a 150 pound woman needs 55 grams of protein each day. That's the amount of protein equivalent to 6 ounces of chicken and 2 cups of milk.
For a 200 pound man, that translates into 72 grams of protein which you can get in 6 ounces of chicken, 2 cups of milk, plus ½ can (2 ounces) of tuna.
But the study found that women who got more protein than this did better at weight loss and preserving muscle. Women on the higher protein diet also got 2 scoops of whey protein per day which added an additional 50 grams of protein. Since whey protein doesn't have any fat or carbohydrate, it's lower in calories than if you were to add 50 grams of protein from other foods.
What are the best foods for protein?
Protein-rich foods include meat, poultry, fish, eggs, beans, tofu, soy products, milk, yogurt and cheese. To keep saturated fat and calories to a minimum, choose poultry breast, fish, egg whites and lean cuts of meat such as sirloin, tenderloin, extra lean ground beef, pork loin and wild game.
Legumes – kidney beans, chick peas, black beans, soybeans, etc. – have no saturated fat and are a good source of fibre, vitamins and minerals as well as protein. One-third cup of beans has roughly the protein equivalent of one ounce of meat, chicken or fish.
Nuts provide protein too but they're high in calories due to their high fat content. For example, one quarter cup of almonds (about 23) delivers 7.5 grams of protein along with 206 calories.
If you like red meat – beef, veal, pork, lamb – keep your intake to less than 18 ounces per week. Higher intakes have been linked with a greater risk of colon cancer. Avoid processed meat including bacon, sausage and deli meats since they too have been associated with a higher colon cancer risk.
Milk, yogurt, kefir and part skim cheese are excellent protein sources to include at meals and snacks. One cup of milk supplies 8 grams of protein, ¾ cup plain low fat yogurt has 10 grams, and ¾ cup of plain kefir delivers about 6 grams.
Soy beverages are also a good source of protein providing about 8 to 9 grams per one cup. Rice and almond beverages are not a nutritional replacement for milk since they're low in protein (1 to 4 grams per cup depending on the brand).
If you're trying to shed weight, be sure to include protein at all meals and snacks. Doing so can help curb your appetite and preserve muscle mass while losing body fat. Spreading your protein out ensures there is a constant supply of amino acids for your muscles.
Whey protein is a popular supplement and it was used in this study. Is it a good alternative to foods?
When you're cutting calories, whey protein power is a convenient way to add extra protein without adding extra calories. While brands vary, most products provide 25 grams of protein and 100 to 120 calories per scoop (28 grams). Whey protein generally contains a higher amount of essential amino acids – amino acids the body can't make on its own – than other protein sources.
Choose a product that's free of artificial flavours and sweeteners. Avoid brands that contain excess sugar in the form of fructose, dextrose and maltodextrin. Pure whey protein powder should have less than 2 grams of sugar per 30 grams of protein. But whey protein isn't for everyone; for some people it can cause bloating and digestive distress.
Protein-packed foods -- protein in brackets (grams)
- Meat, 3 oz. (21-25)
- Poultry breast, 3 oz. (25)
- Salmon, 3 oz. (19)
- Tilapia, 3 oz. (22)
- Tuna, 2 ounces (about 1/2 can) (15)
- Egg, 1 whole, large (6)
- Egg, 1 white, large (3)
- Milk, 1 cup (8)
- Yogurt, plain, 3/4 cup (10)
- Yogurt, Greek, 3/4 cup (18-21)
- Cheese, hard, part skim, 1 ounce (7)
- Black beans, cooked, 3/4 cup (11.5)
- Lentils, cooked, 3/4 cup (13.4)
- Soybeans, cooked, 3/4 cup (21.5)
- Tofu, firm, 3/4 cup (30)
- Almonds, 1/4 cup (7.5)
- Whey protein powder, 1 scoop (28 g) (20-30)