I've just started weight training. How much protein do I need?
Building muscle uses up protein, but that doesn't necessarily mean you have to take in more protein than you normally do. An upper-level, intense bodybuilding routine may temporarily up protein requirements to about 0.8 grams of protein per pound of body weight (140 grams for a 175 lb. athlete), but this is probably too high for most people. Starting a weight program increases your protein requirements by a small amount, but only in the beginning stages of training. On average, dividing your weight in pounds by 2 should give you the number of grams of protein you need. Keep in mind that extra protein isn't "saved for later." It's broken down and either stored as fat or used for energy. Plus, protein overload increases calcium loss from bones. Most Americans already get more than enough protein, and more isn't necessarily better - even for weight lifters.
What can you tell me about Hydroxycut?
Hydroxycut, a "fat-burning" supplement designed to help you get lean almost instantly, claims it can "burn 613 percent more fat." Many students claim "it's the bomb" as far as energy and fat loss are concerned. Unfortunately, Hydroxycut doesn't deliver on all of its claims, and chronic users may damage their heart muscle.
The so-called "effective" ingredients in Hydroxycut and other similar products are ma huang, guarana, and willow bark. Ma huang is an herb containing ephedra, a chemical stimulant that is used in over-the-counter asthma medicines (popular model Niki Taylor's younger sister died from overdosing on this chemical). Guarana contributes a jolt of caffeine, and willow bark adds salicin, which is basically the same thing as aspirin. Some fat-burners also contain a plethora of other substances such as chromium picolinate, pyruvate, and hydroxycitric acid, all said to help dieters lose weight.
The studies done on the efficacy of these products have yet to make it into reputable journals. But there have been good studies that show an increased risk of high blood pressure, fatal heart attacks, and strokes with the use of weight loss products that contain ephedra.
Clearly, the ads are very deceptive regarding safety. Studies of efficacy are about 50/50, with half showing marginally positive results and half showing none at all. What is interesting is that commercial manufacturers often fund the studies that indicate beneficial effects of ephedra.
Some experts will claim that these products do have a small positive effect, but only when used in combination with diet and exercise. Therefore, it is hard to say how much weight loss is due to Hydroxycut and how much is due to improved eating and exercise habits.
Whether it works is one thing; whether it is safe is another. Any minor effect you might get from these pills can be achieved with better and quicker results through exercise and dieting, and it isn't worth the risks.
Will I gain weight faster if I eat before bedtime?
Your body's need for energy fluctuates over a 24-hour period, but the food-to-energy cycle isn't so rapid that what you eat at bedtime will be sitting on your hips as fat by morning. It's more of an issue of how much you eat rather than when you eat. Lots of students get into the habit of "grazing" on high-fat munchies like pizza and chips, in addition to regular meals, and end up eating more calories than they need to maintain their weight. But if you work an odd schedule and end up eating dinner late, you won't sabotage your weight as long as you eat a reasonably healthful meal.
Can soy protein help you lose weight?
No. Despite claims you may have seen like "soy stops fat" or "clinically proven for weight loss" on soy-based meal replacements, there is no component in soy that promotes weight loss. However, soy protein (found in tofu, tempeh, soy burgers, and other foods) has been shown to lower cholesterol levels and contribute to "heart health." If products containing soy are found to be effective for weight loss, it is only because people are likely replacing high-calorie foods with low-calorie soy, not because soy has any miracle "fat-stopping" ingredient.
What is Tyrosine?
Tyrosine is one of 20 amino acids - the building blocks of protein. It is nonessential, meaning our bodies can make it themselves (from proteins), and don't have to get it from food. In the body, tyrosine is converted into neurotransmitters that relay electrical "messages" throughout the nervous system.
A supplement form of tyrosine (sometimes called L-Tyrosine) is marketed for depression, improving mental alertness, easing alcohol withdrawal, Parkinson's disease, and Alzheimer's disease, among other disorders. However, there is no evidence that taking tyrosine or any other single amino acid offers any of these benefits.
In fact, the body doesn't recognize the difference between amino acid supplements and amino acids from protein in food. But supplements of any single amino acid may interfere with the absorption of amino acids we can't actually make on our own.
The amount of tyrosine needed for optimal health is achieved merely by eating protein. Even vegetarian diets provide ample tyrosine. But too much protein, which can happen with amino acid supplements, can harm the kidneys and cause dehydration.
Do carbohydrates make you fat?
No. You will not find a single, credible nutrition expert who will tell you that carbohydrates make you fat. But if you don't exercise and you eat lots of "fat-free" cookies, chances are you're going to put on weight because of the excess calories.
Experts agree that Americans tend to misinterpret "The Food Guide Pyramid" with the mentality that you can eat as much as you want as long as you avoid fat. This thinking has caused an influx of products filled with sugar and high in calories but bearing the claim "fat-free." Americans have continued to pack on the pounds ever since - not because we eat carbohydrates, but because we avoid fat (keeping us from feeling full), eat too much sugar, and don't get enough fiber.
There is some debate about the difference between whole grains like oats, barley, millet, and bulgur wheat, and refined grains such as white rice, potatoes, and bread. Experts agree that whole grains should be emphasized over refined grains because they are high in fiber, which fills you up and keeps you from overeating.
Too many calories will make you fat, and they can come from any high-calorie food, including cheeseburgers, french fries, soda, candy, dessert, or anything else consumed in excess - even protein bars or shakes.
What's the best way to burn fat?
Strengthening muscles through weight training gives you the biggest bang for your buck when it comes to fat burning. For cardiovascular work, you'll get the same overall fat burn per session for a shorter, harder workout than you would from a longer, slower workout.
But you'd be better off including some tough workouts or interval training in your aerobic routine on a regular basis. This is because high-intensity training helps strengthen "fast-twitch" muscle fibers, which will increase the amount of calories you burn at rest. In addition, workouts where you really push yourself burn calories at a much faster rate and continue to burn calories for a longer period of time after you stop exercising than easy workouts. When crunched for time, take advantage of short interval-training sessions (20-30 minutes) for fat-burn and skip the hour on the treadmill.
Valerie Green is a combined Nutrition and Masters of Public Health student at Tufts. You can e-mail your questions or topic ideas to valerie.green@tufts.edu.
