One of the questions most commonly asked by people who wish to lose weight involves the amount of protein they should ingest to prevent loss of
muscle mass. Dieting is a very stressful procedure, and we want to maintain as much muscle as possible while shedding excess fatty acids. An
equally important dietary factor, however, is carbohydrate consumption, for we need enough energy to do workouts and conduct our daily lives.
We must also take in some fats to maintain our skin and internal metabolic processes. The critical question is, what should our relative balance
of proteins, carbohydrates and fats be if we are to remain healthy while losing weight? There is no ideal solution, especially for very
low-calorie diets of from 1,200 to \1,600 calories per day.
Many bodybuilders prefer to take in roughly one gram of protein for every pound they weigh. This guideline implies a 200-pound athlete should ingest about 200 grams of protein. Protein generates roughly 4.0 calories of energy per gram consumed, so 200 grams of protein provides 800 calories. Given a diet of 1,400 calories per day, this level of protein consumption equals 57.1 percent of one's total daily intake. That leaves only 600 calories (42.9 percent) for fats and carbohydrates. Clearly we cannot consume what many consider to be an optimal level of protein while keeping our overall nutrient balance anywhere near adequate during low-calorie dieting phases.
We probably don't need as much protein as many athletes think to maintain our basic needs. In fact, most nutritionists contend that we require only 0.8 grams of protein per kilogram of bodyweight, which works out to a mere 0.36 grams of protein per pound. If 1 I weighed 250 pounds, I would have to I ingest 90 grams of protein to meet my I basic needs. A person with an active life I and heavy workout schedule could assume I a basic need of 0.5 grams of protein per | pound. Granted, higher protein levels may I elicit androgenic responses that facilitate I muscle growth and strength development, I but I am willing to forsake these effects in | order to maintain a safe nutrient balance I while losing weight. My lifestyle is not very active, and well over 25 percent of my 1 bodyweight is fat. Fat is less metabolically active than lean mass, so I opt to ingest about 100 to 110 grams of protein per day. Still, 110 grams of protein generates 440 - calories, leaving me with only 960 calories I to accommodate other nutrients on a 1 1,400-calorie-per-day diet.
In addition to protein we need carbohydrates for energy, 125 to 175 grams per day in the view of many nutritional experts. That's about one gram per pound. A 250-pound man would need to take in 250 I grams of carbohydrates to meet this ideal, but if he had a high percentage of bodyfat this figure could be reduced slightly. Each gram of carbohydrate generates 4.0 calories, and 250 grams of them costs a whopping 1,000 calories. Thus my protein and carbohydrate needs equal a lofty 1,440 calories (440 + 1,000). I've already exceeded my diet's maximum daily calorie level, and I haven't even gotten to fats yet!
Obviously I must compromise on the amount of carbohydrates in my diet if I am to maintain adequate protein level and at least some fat intake. Cutting carbohydrates below my requirements has a harsh cost in terms of the energy that is available to conduct activities. Since our bodies will turn to protein reserves to meet energy needs, we risk losing lean muscle mass if we make extremely drastic cuts in carbohydrates. At first I chose to reduce my carbohydrate level to 175 grams per day, which cost me about 700 calories. It has also cost me a great deal of strength as my diet proceeded, but such is the world of very low-calorie dieting. The average daily energy consumption I planned is 1,140 calories in proteins and complex carbohydrates, leaving only 260 calories for fat.
Fat is very expensive calorically, but we need it for skin growth and other important metabolic functions, including those that maintain blood pressure. At 9.0 calories per gram I could consume only around 29 grams of fat per day if I were to maintain a daily diet of 1,400 calories. This fat consumption was aimed at linoleic and linolenic fatty acids because our bodies cannot produce these essential nutrients. Fortunately most vegetable oils contain these substances, so they can be easily acquired. My fat intake is still very inadequate. It represents a mere 18.6 percent of my daily caloric intake, far less than the average 25 to 30 percent fat intake of the typical American diet. This low had its cost in maintaining body and blood pressure, so some ; became necessary. If we increase consumption we have to either increase caloric consumption or cut back proteins and/or carbohydrates, which ready at very low levels, ere is no happy solution to dietary ices when one is engaged in a very calorie diet, and changes are often led as we pick up on the signals our bodies send. I had to increase carbohydrate and fat intake by 100 calories each as my diet entered its sixth month, and my overall caloric consumption rose to 1,600 per day. Daily weight loss was excellent under le 1,400-calorie regimen. I dropped from 331.5 to 251 pounds in just 180 days. My 80.5-pound loss represents an average reduction of 0.45 pounds per day, but all has not been happiness and light. For example, my strength fell apart, and I was also losing too much lean bodyweight. My bench went from 320 pounds for 20 reps to 320 for a mere 3 repetitions. On the other hand I can now jog for three or four miles whereas at the beginning of my diet I could not jog even half a mile.
My nutrient consumption varies from day to day according to my activities. On my three weekly weight-training days I tend to increase my protein intake to over 120 grams per day, while on the remaining days I reduce this level in favor of more carbohydrates and fats. This is a high-protein/low-fat weight-reduction diet, and it has a number of theoretical benefits that may outweigh its costs. Most important, the relatively high protein intake lessens the normal decline in metabolic rate that often accompanies dieting, and it also appears to maintain a positive nitrogen balance. (Whitehead, McNeill & Smith, 1996) These factors can facilitate weight loss and the retention of lean body-weight, as demonstrated in both human and animal studies. (Jan. 1988; Oi et al., 1987; Gougeon, Pencharz & Marliss, 1995) Low-fat diets may help alleviate the possibility of gallstone formation, a considerable risk in obese subjects who go on very low-calorie diets. (Heshka et al., 1996)
On the negative side relatively high protein consumption may exacerbate the normal ketosis that can accompany dieting and exercise. (See Mitchell et al., 1995.) Ketosis involves the overabundance of nitrogen-rich ketone bodies in the blood. This condition often manifests itself by peculiar-smelling sweat and breath. In its more severe forms ketosis can stress the kidneys, liver and other internal organs, so it should be avoided. This is a relatively rare disorder, however, and the level of protein consumption in my diet is not likely to result in ketosis.
You now have a good idea of how to balance proteins, carbohydrates and fats during dieting phases, although you must match this balance to your specific needs and biological predispositions. Our attention will turn next to a detailed analysis of how exercise influences the dieting process. We shall quickly see that exercise isn't just a means of burning extra calories, for it can also produce a number of other beneficial effects that make dieting a more successful endeavor.