Protein and Hunger
Are Americans eating too much food because we're not eating enough protein?
A recent study showed that when subjects ate a 10% protein diet instead of a 15% protein diet, they ate 12% more energy over four days. Most of the increased food intake was due to snacking. Eating a 25% protein diet caused no more eating than the 15% protein diet.
Protein consumption in America has decreased from 14% in 1961 to 12.5% in 2000, and this decrease was accompanied by a 14% increase in nonprotein food intake, according to previous research.
This makes sense to me. The body needs protein. If it doesn't get enough protein, it will tell you to keep eating, even if the snack foods you choose are mostly carbohydrate with just a little protein.
I suspect the same phenomenon applies to foods without sufficient vitamins and minerals, like a lot of the processed foods people eat today and even whole foods that are grown in mineral-depleted soils.
Interestingly, some researchers formerly advocating eating as much low-GI carbohydrate as possible are now focussing on protein. Low-GI carbs like whole grains may contain a little more protein than highly processed carbs like white bread, but they're still relatively low in protein compared to foods like meat and tofu. And when you eat a lot of carbohydrate foods, you're apt to eat less high-protein foods like meat.
So the fact that some who were emphasizing carbohydrate are now emphasizing protein means that opinions in the nutritional world are changing.
Some people worry that "high-protein" diets are not healthy. So let's see how much protein would be in a 10%, 15%, and 25% protein diet.
Let's take a 1500-calorie diet. Protein would be 150, 225, and 375 calories from protein. Protein has 4 calories per gram, so that would be 37.5, 56.25, and 93.75 grams of protein, respectively.
There are approximately 7 grams of protein in an ounce of meat, so this would be about 5 oz of meat a day in the 10% diet, about 8 oz in the 15% diet, and about 13 oz in the 25% diet. Not all that much.
But a cup of a typical breakfast cereal, Cheerios, or a slice of multigrain bread, has only about 3 grams of protein out of the hundreds of grams one needs a day. A cup of brown rice has about 4.5 grams of protein.
A cup of cooked kidney beans has more, about 15 grams of protein. You could reach your 15% protein goal on a 1500-calorie diet with almost 4 cups of beans a day. But how many Americans eat that many beans (and would anyone ride in an elevator if they did?).
So it's understandable that many Americans eating a lot of cereal, bread, and other starchy foods may not be eating enough protein to curb their hunger.
Remember that these calculations are based on a 1500-calorie diet and your needs might be different. Also, when it comes to protein, the really important thing is whether you're getting enough to satisfy your muscles, and this depends on lean muscle mass. As an approximation, you need about 0.8 grams per kilogram of body weight, or 0.3636 per pound.
The bigger you are (not counting fat), the more protein you need.
But these numbers suggest that many Americans might not be getting enough protein, despite the national craving for hamburgers. Not eating enough protein might make us eat even more food, and if we've been warned about the dangers of saturated fat in meat, most of that food would not be high in protein.
Then we'd gain weight, and in an effort to lose weight, we'd eat a lot of salads, which are not usually high in protein. So we'd crave more food. You can see how a vicious cycle might ensue.
The most difficult thing about dieting is dealing with hunger. It's almost impossible to resist food when it's available and you're hungry. I find that a low-carb diet with as much meat as I want (not really that much) curbs my hunger. Low-carb diets permit more meat than low-fat diets. It all makes sense.