Proteins, Carbs, and Fats : The good, the bad, and the skinny on macronutients and weight management ( Part 1)

For the last 100 years, people have debated the role of proteins, fats, and carbohydrates in weight gain. And it seems that every few years, we learn something new that changes our whole perspective. Just what do each of these nutrients have to do with the size of our waists? Lets look at proteins.

Proteins

Proteins are made up of amino acids and are found in a variety of food sources. In our bodies, proteins are necessary for the formation of antibodies, transporting nutrients like oxygen to our tissues (through hemoglobin), providing structural support ( in collagen and elastin in our tendons and ligaments), for building and repair of tissues, and for muscle contraction.

The average person needs about .34 grams of protein per pound of body weight in their diet to meet the body's need for protein. A 120 pound woman would need approximately 2-3 servings of a protein food per day to meet these requirements ( i.e. 6-7 ounces of meat ). Endurance athletes and body builders need a bit more.

Its not difficult to get adequate protein today. Our best sources of protein are animal sources, such as meat, fish, poultry, eggs, and dairy products. The protein in animal products are considered "complete proteins" because they contain all of the essential building blocks needed by the body.

Vegetable proteins are considered "incomplete" because each individual vegetable lacks certain amino acids needed by our bodies. By combining "complementary proteins", vegetarians can make sure they are receiving all of the essential amino acids their bodies need.

Protein can be a great tool for weight control for a couple of reasons. Adding protein to a meal or snack slows the rate at which blood sugar is increased. This blood sugar stabilizing effect keeps blood levels of insulin at bay, discouraging fat storage. It also keeps us full longer, staving off cravings and binges. Consuming a protein filled snack about an hour before a meal helps us eat fewer calories during that meal. Adding protein to our breakfast keeps us fuller all day, preventing overeating.

A recent concern about protein foods involves the use of soy products. Soy products are rich in isoflavones - chemicals that are rich antioxidants, but also act as phytoestrogens ( plant based chemicals that act similarly to hormones in our bodies).

Soy products were previously thought to be a heart friendly alternative to animal protein, as they are complete proteins, low in fat, and contain isoflavones. They were thought to lower cholesterol, and had been promoted as part of a heart healthy diet.

Soy products have also been promoted for women going through menopause, as the phytoestrogens seemed to mimic estrogen in the body, reducing menopausal symptoms, without the cancerous effects.

Today we know, however, that soy isoflavones actually do have estrogenic effects on our bodies, and the use of soy products is now thought to be linked to.....

thyroid insufficiency ( especially in those deficient in iodine)
cancer
lower testosterone levels in men (leading to sexual dysfunction and infertility)

The American Heart Association has now stated that soy products provide no benefits to the heart, and an article in the Journal of the American Medical Association has reported that soy isoflavones do not improve cholesterol, cognitive function, or bone mineral density.

Several European countries have banned or limited the use of soy in infant formulas. Soy based infant formulas contain about 20,000 times the phytoestrogen content found in human breast milk.

The problem with soy may not necessarily be due to the soy itself, but rather the way in which soy is processed and consumed in America. The typical Asian diet contains regular consumption of soy products, however, they consume products like tofu, miso, and tempeh- soy products that are fermented. They also are consumed as condiments, rather than as the main component of a meal, in doses of approximately 10-30 mg of soy isoflavones per day. In America, we consume many soy products such as soy burgers, hot dogs, nutrition bars, and other highly processed soy foods, ( some form of soy is found in virtually all processed foods ), and in large amounts, around 80-100 mg isoflavones per day.

Reports of reduced fertility have been found among men drinking just 3 cups of soymilk a day.

The problems we are seeing with soy in America have more to due with the type of processing of the product, and the large amounts in our food supply-leading to over consumption. To safely enjoy soy in your diet, do as the Japanese, and stick with products like fermented tofu (check labels carefully, not all tofu is fermented), and limit your consumption to an occasional amount.