Q What provides more fuel: carbohydrates, protein, or fat?
C.S., Philadelphia, PA

A Carbohydrate is a more efficient fuel for producing ATP (ultimate source of energy in our bodies), but more fat can be stored so it keeps us going in endurance activities - it helps conserve the more limited carbohydrate stores. In a word, the answer to the question is: FAT! Remember that fat has nine calories per gram, but protein and carbohydrates both have just four calories per gram. In other words, fat is more energy-dense. We store fat to burn when we need it; it is in constant supply. It only becomes a problem when we become too inactive. Fat that isn't burned just continues going into our storage depots (hips, thighs, abdomens, etc.). There is no limit to our fat storage capacity.

Q I have a friend who recently discovered that she has diabetes - not the insulin-dependent type - and I am interested in what the disease is all about, and what its common treatments are.
S.M., San Jose, CA

A There are two types of diabetes: Type I, or insulin-dependent diabetes , and Type II (formerly called adult-onset diabetes) or non-insulin-dependent diabetes. It sounds like your friend has Type II, which is a metabolic disorder characterized by insufficient production of, or use of, insulin, which is a hormone that helps move glucose from the blood into the body's cells. The result is that blood glucose levels rise to abnormally high levels. The high blood glucose is filtered out through the urine. At the same time, water is not reabsorbed at a normal rate in the kidneys, resulting in a large loss of both water and glucose. Decreased glucose in the cells result in abnormal reliance on fat metabolism for energy, which results in acidosis (abnormal acidity in the blood), which can cause diabetic coma.

Other problems that can result from diabetes include arteriosclerosis, small blood vessel and nerve disease, and susceptibility to infection.

It seems that diabetes is incurable, but controllable by diet and exercise, and sometimes medication.

Exercise helps diabetics by raising tissue sensitivity to insulin, which helps move glucose into the cells; however, too much can cause hypoglycemia (low blood sugar), which may manifest itself in faintness, excessive fatigue, loss of consciousness, or a seizure. Other less severe symptoms may include headache, sweating, shakiness, slurred speech, irritability, and poor coordination. Aerobic exercise is important because it is easy to control its length and intensity, and those two factors, in addition to a consistent time, seem to be especially important - they help glucose regulation. Weight training can benefit a diabetic by raising metabolism, which helps to control weight, and being too fat is thought to be a major factor in the onset of diabetes, and, therefore, weight (fat) loss, a significant factor in its control.

Q How can I keep my bananas fresh longer? The skins get black spots, and the fruit turns to mush in a couple of days.
D.B.F., Vancouver, WA

A As an aspiring fitness savant, I do have a hint (not from Heloise), and that is to put them in a paper bag, and store them in your refrigerator. They will stay fresh for a couple of extra days.

Q What is trans fat, that I hear about so much lately?
M.N.F., New York City

A Trans fat (a.k.a. trans fatty acid) is "hidden fat" as far as nutrition labels on food goes. There is currently no requirement to count it as "fat." It is produced by the process of "hydrogenation," which is used to thicken a variety of food products. Trans fat promotes classic saturated fat effects - lowers HDL, raises LDL - possibly more than saturated fat itself. Beware of products whose ingredients include hydrogenated or partially hydrogenated "stuff." It would be prudent to pay attention to where it falls in the ingredients list.

Q I drink a lot of beer as part of my recent movement toward a healthier diet. Is that a good idea?
N.S.S., Boise, ID

A Yes, if your goal is to promote obesity. Beer is particularly good at producing fat because the alcohol content is quickly "burned," leaving the remainder to be stored as fat.

Q Are sports drinks worthwhile?
C.M., San Jose, CA

A I have to equivocate a little here: "yes" and "no". For the average fitness athlete, the drink of choice is water. Dehydration is the concern here, and water takes care of that very nicely. However, if you happen to be a world-class endurance athlete, or any kind of endurance athlete for that matter, you may derive some benefit from a sports drink containing 6-10% (or maybe 5-7%, according to one source) glucose. Note that we are talking about an activity lasting over two hours (e.g., a marathon or triathlon, or maybe even an intense weight workout). Also note that they are counter productive for people trying to lose weight.

A more specific answer is that for a 20-30 minute workout, water is just fine. A cup 30 minutes before exercise, and a cup immediately after should do the trick. It seems that sports drinks do rehydrate you faster after exercise than water. It may be that water shuts down the thirst mechanism faster, causing people to stop drinking before full rehydration. The minerals in sports drinks also seem to retard urine production, which also helps rehydration. But sports drinks before exercise should be avoided. They seem to retard release of fatty acids from fat cells, for about 30 minutes, thereby robbing you of your primary fuel, and forcing excessive use of glycogen. A sports drink during or after exercise is OK because fatty acids are already released. Note that fruit juices are normally about 10% glucose and fructose, making them harder to absorb. So water is best for short exercise sessions, and sports drinks seem to have benefits for longer duration exercise.

Q I have heard that it is beneficial to eat some carbohydrates after a workout. There is supposedly a "window" during which our glycogen supplies are restored without us having to wait for the normal hours- long cycle, but I have heard that it is 15 minutes, or 30 minutes, or one hour. What's the story?
H.G.M., Eau Claire, WIS

A This is a fortuitous time for you to ask this question, H.G. I just heard the answer from my friend, Covert Bailey. The probable reason for the seeming ambiguity is that the "window" is actually about two hours long, but the sooner you use it, the more efficiently the refueling goes. By the time the two hour mark comes up, the process has become somewhat like trying to pour gas in a can with a narrow spout, you are likely to spill a lot, and not get the can completely filled.

Q I am now eating a lot of low-fat and non-fat food, but I am not losing weight. Did I give up my twinkies and beer for nothing?
I.T.H., Boston, Mass

A There seems to be some confusion about low- or non-fat and calories. It seems to be true that reducing the amount of fat intake is a reasonable goal, but not at the complete neglect of calories. Even non-fat food can be loaded with calories, which the body may convert to ....... fat, depending on its needs.

Q I have heard that fairly high intensity exercise burns fat, but you have said that moderate intensity exercise does. Which is correct?
D.F., Pittsburgh, PA

A "Moderate" exercise is a relative concept. In a well-trained athlete, "moderate" can be a fairly intense level compared to a less-well-trained person for whom just moving is moderate exercise. A well-trained individual burns fat quicker, thus longer, than his/her opposite, who, exercising the same length of time, burns less fat.

Q I always thought cross training was performing different training activities, such as swimming, running, and cycling as preparation for a triathlon; or weight training and jogging for fitness. But I have recently heard a new definition that had to do with collateral training effects.
D.W.C., Fresno, CA

A It turns out that there are two widely different meanings to the term. One is the most widely used definition, which is participating in multiple sports activities to maximize fitness. The second definition may actually be the oldest, and it refers to collateral training. This is a significant concept that says that exercise has both neurologic and systemic affects, i.e., if you train only your right arm, your left arm will also receive some benefit. This benefit appears to work between arms, between legs, from legs to arms, but not from arms to legs (the muscles are thought to be too small to cause systemic changes, and there are no neural connections between arms and legs. This concept is of particular importance to those with injuries. An example of what I am saying is: if one had a broken right arm, and did arm curls with the left, atrophy of the right arm would be less than would ordinarily be expected. This is a good example of a concept I preach: "do what you can do."

Q Why is it that everything I like to eat - it tastes good and fills me up - contains too much fat? I know life isn't fair, but.....
R.F., Palo Alto, CA

A I don't know, but I think it's some kind of divine justice ..... or injustice. Part of the answer to this question may be that the extra calorie density of fat makes it more filling.

Q Which is easiest to get rid of, android (or male pattern fat - pot bellies), or gynoid (female pattern fat - hips/thighs)?
Y.M.K.F., Los Altos, CA

A Covert says android. It carries the highest health risks, but is the easiest to lose.

Q In the last issue (August '94) of the MAF FITNESS NEWSLETTER, there was some information on protein intake, which I found slightly confusing - I don't know my weight in kilograms. Can you be a little more lucid on this subject?
A.F., Palo alto, CA

A Yes, I understand the problem, and I can help. People need roughly 30 grams of protein per day. About 25 for smaller people. The RDA (Recommended Daily Allowance), which is conservatively set at about twice the normal daily need, is 50-60 grams per day, which should easily cover everyone, including high need groups like growing children, pregnant women, people with broken bones, and high-intensity athletes. Most Americans get more than enough without ever thinking about it.

Q I recently read some disconcerting information about estrogen replacement and osteoporosis. It has long been thought that post-menopausal women typically need estrogen replacement to help stave off the effects of osteoporosis (loss of bone density). I know that isn't the only reason for estrogen treatment, but the other stuff isn't relevant to my question. It was discovered that estrogen replacement led to side effects, the worst of which was the potential for endometrial cancer in women with an intact uterus. Then it was discovered that this side effect was eradicated by the addition of progesterone. For one reason or another, instead of using natural progesterone, synthetic drugs named progestins became popular among doctors. They did eliminate the incidences of endometrial cancer, but, they have their own set of side effects not shared by natural progesterone: possible pregnancy problems, and possible elevation of blood pressure.

In addition, it looks like estrogen may not really affect osteoporosis as had long been thought. Bone strength is affected by two components: osteoclasts, that travel through bone tissue looking for bone that needs to be replaced (like old mineralized and hardened bone), and then dissolving these areas leaving cavities; then osteoblasts come along and fill them with new bone tissue. Estrogen seemingly retards osteoporosis by slowing the loss of bone tissue caused by osteoclasts, but without any affect on bone tissue production by osteoblasts. Estrogen before menopause may slow osteoporosis, but may have no effect after.

Progesterone, however, seems to lead to production of osteoclasts, which result in new bone formation, and thereby prevent osteoporosis. Any comments?
T.K.F., San Francisco, CA

A Whew! What a question. Your question certainly raises some intriguing questions, which the target population should put to their doctors. I am not qualified to make any substantial comments on this subject, and I will keep my opinions to myself.

Q Is there anything that we can eat that is sweet, but not excessively fat?
R.F, Palo Alto, CA

A Yes. Fruit, for instance, or there are a number of non-fat and low-fat deserts/snack foods on the market now: ice cream, frozen yogurt, cookies, and other goodies. Also, things like frozen juice bars. for snacks, there are things like pretzels, many of which are non-fat, but, as with all of these low- or non-fat items, beware of high calories usually from sugar in one of its innocuous sounding forms (like corn syrup), and high salt content may be a problem for those of you who have a salt intolerance. When you shop, read the nutrition labels carefully.

Q I recently had a blood test that indicated a high triglyceride level, should I worry?
D.Q., Spain

A First of all, I am not a medical doctor (or any other kind, for that matter), so I can only give you my opinion. Which is that triglycerides are the basic storage form of fat, and when found in excessive amounts in the blood, can indicate a problem. Usually a triglyceride test would include cholesterol and HDL/LDL levels as well. A full evaluation of all blood factors tested would be evaluated. Risk would likely consider triglyceride levels and cholesterol High amounts of both could portend atherosclorosis and potential heart attack or stroke problems. High amounts of HDL and a low LDL level would lessen your risk, but I think re-evaluation of your diet would be in order.

Q I am an 87 year old man, could I benefit from weight training?
I.A.O., Boston, Mass

A Definitely. It can increase strength, flexibility(*) , overall muscle tone, and a host (plethora, if you are a sports fan) of other things. Even minimal amounts of weight training can yield significant results. There are a number of support muscles active (in isometric contraction) with every exercise we do. For instance, when one does arm curls, in addition to the prime movers; abdominal, shoulder, and back muscles, and legs, if you're standing, are used to maintain posture.

(*) Flexibility is not improved by weight training according to many fitness experts; however, range-of-motion can be improved, and I equate that to flexibility.

Q Is it true that women actually can build muscle mass (bulk-up)? For years I have heard that they normally couldn't because of their usually lower testosterone levels.
O.O., Toontown, CA

A Recent studies have shown that women can increase their muscle mass equally as well as men. The percentage of change for similar exercise levels is nearly equal - men are typically larger because they normally have more muscle fibers to start with. After puberty, testosterone appears not to be a factor in muscle growth. Fibers increase in size in both men and women in response to exercise. This is enlightening to me - everything I have previously learned about muscle hypertrophy (growth) said that larger male muscles were a result of their higher testosterone levels, and not just before puberty. The implication has always been that women's muscles simply do not respond to exercise as do men's. This new (to most of us) finding helps to explain the high levels of muscular development in competitive, female bodybuilders. They aren't genetic freaks, or all take drugs, after all.

Q I have always heard that I should warm-up before a sports activity, whether it's something like weight training or running. What is a warm-up intended to accomplish?
N.M.K.F., Mtn Vw, CA

A I used to be a serious recreational runner, and was always afraid to do much of a warm-up before, say a 10K, because I thought I would use up too much energy before the race. I have since been enlightened about the purpose of a warm-up. A warm muscle is simply more prepared for exercise than a cold one. Oxygen and fuel are delivered faster to a warm muscle. This more-or-less explains "second wind." When you start cold, your system just isn't ready to go - like your car in the morning. And, significantly, a warm muscle burns fat (our primary fuel) sooner than a cold muscle. The heart functions without the irregularities sometimes found after a cold start; coordination is improved at the start of exercise; and a warm muscle is more elastic, which helps prevent injuries.