I found myself accepting fewer Internet health-and-fitness writing assignments last summer, but it wasn't from a lack of motivation. The reason can be traced back to something my father said to me repeatedly when I was small.

"Do something right or don't do it at all."Most of the sites I work for want no more than four or five 75-to-100 word paragraphs written about a rather specific topic they select. And too often, I feel that covering that topic in less than 500 words doesn't do it justice.So I don't accept the assignment. Since I don't believe such a short article would turn out "right," I don't turn one out at all.Conversely, I don't like "Fitness Master" articles to run too long. Preferably, each should be 800 to 900 words, the typical length of a newspaper column. But explaining science-related stuff sometimes requires more words than that.Which means a part 2 a week later.Last time, you read about why I consider manipulating body weight "child's play."While you might argue against my claim because you personally find that doing so is hard to do given the way society is structured today, the science that creates weight loss or weight gain isn't hard to follow. But it certainly can't be explained properly in a single "Fitness Master" column, let alone the typical-sized health articles you find on the Internet today.Last week's column explained insulin's role in transporting nutrients to the muscle cells and that your choice of carbohydrates determines the amount of insulin secreted to do that job.Complex carbs break down slowly and temper the insulin response, meaning more glucose gets stored as energy and less as fat. So complex carbs should be your carbohydrate of choice, a fact that remains true even when you're ravenous and feel the need for immediate energy.Consume a meal of mainly simple carbs when you're ravenous, for example, and it's just about guaranteed that you'll feel just as hungry 90 minutes later about the time it takes for insulin all of its escorting a process chronicled in detail in last week's article. (You can find it on The Times News' web site if you missed it.)But there's even more to consider about carbohydrates besides simple and complex.The digestion of the other macronutrients, protein and fat, when eaten in concert with carbs also slows the digestion of them, which leads to the inevitable question: what balance of nutrients allows enough insulin to transport glucose and amino acids to the muscles but not so much that it leads to the production of fat?What John Parrillo, a nutritional expert who primarily works with bodybuilders, suggests is something that I've written here a number of times primarily because it works for virtually anybody. Eat small, frequent meals, (generally no more than 600 calories) that contain a lean protein source, a starchy vegetable, and a fibrous one.You alter the exact ratio of these to suit your goals and body type. Someone looking to lose weight gain does better with a 1:1 ratio of carbs to protein which is a large amount of protein compared to what the typical American is accustomed to. Someone looking to gain muscle but not too much body fat fares better when the ratio is 2:1.Conventional dietary fats not the MCT oil Parrillo touts to add calories when bodybuilders are trying to add muscle should comprise no more than 10 percent of your total calories.Eating in this manner stabilizes blood sugar levels throughout the day, making the chance that you store fat less likely. Another ploy Parrillo passes along to those trying to lose weight: cut out the starchy carbs from the last meal of the day. The reason he suggests this is so you can burn fat throughout the night by secreting another powerful hormone, glucagon.Think of glucagon as insulin's opposite. The pancreas secretes glucagon to raise rather than decrease blood sugar levels. Where insulin decreases blood sugar levels by escorting blood sugar to the muscle cells or the fat stores, glucagon increases it by stimulating the liver to release stored glucose as well stored fat for energy.If your body is secreting glucagon, you're burning body fat.Continually burning body fat, not specifically losing a set amount of overall body weight quickly, is the key in maintaining a healthy body weight.But there's a dangerous element to glucagon secretion. Prolonged elevated secretion can cause you to burn muscle mass. This is what happens invariably towards the end of a long and hard exertion, such as the last third of a four-hour bicycle ride or the last six miles of a marathon.That's why consuming protein along with carbs as a recovery meal after prolonged exercise is suggested, preferably within 30 minutes of its conclusion. Remember, it always takes longer to build back muscle than tear it down, so take care.To close, keep this utmost in mind. Whether your body secretes insulin or glucagon is determined entirely by the ratio of carbohydrates to protein in your diet. And who decides that?You.