Taking Control of Your Dietary Composition Part 5

Energy balance is the sole determinant of whether your body increases or decreases its fat stores. If you take in less energy than you expend, your body will have no choice but to satisfy the deficit by accessing fuel reserves and the predominant way that the body stores energy is in adipose tissue (body fat). Adipose is a dense source of energy; for example, one pound can be cashed in for 3,500 calories, which is enough to power a 35-mile walk for the average-sized person!

Discounting small variations in metabolic efficiency, a calorie is a calorie regardless of the food source. So, if you ingest 3,500 less than you use over the course of a week, you'll lose a pound no matter what you eat to satisfy the requirement. This means that if your goal is to lose a pound in the next seven days and you decide to eat eight chocolate frosted donuts each day and nothing more, you'll achieve your objective as long as your energetic outlay is enough to cover that cost plus the deficit. For example, if you used 2,660 calories each day (each donut contains 270 calories, so eight would add up to 2,160 to which you would add the 500 calorie deficit that's necessary to promote the desired fat loss), you'd be good to go. To put this into perspective, a 150-pound person requires approximately one calorie each minute of the day just to stay alive (i.e., to satisfy their basal metabolic requirement). So, if you do the math, you'll discover that simply lying in bed all day while you eat those donuts would already have you covering more than half of your required outlay (24 hours x 60 minutes/hour x 1 calorie/minute = 1,440 calories).

The take-home message is that fat loss is less about what you eat and more about how much. But this does not mean that the you-are-what-you-eat mantra is not warranted and if we delve further into this donut diet, you'll understand why. Energy in food comes in three forms - protein, carbohydrate and fat. These components are called macronutrients because we need them in relatively large amounts. Foods also contain micronutrients that we need in smaller amounts (e.g., vitamins and minerals), but these do not contribute energy to the diet. Generally speaking, a gram of protein provides four calories as does a gram of carbohydrate. On the other hand, a gram of fat contributes nine, which exemplifies its dense energetic nature (see above). This means that if you multiply the protein and carbohydrate content of a food by four and the fat content by nine, the sum of the three products will approximate the caloric content of the food. For example, the donut has three grams of protein (and, therefore, a contribution of 12 calories from this macronutrient), 31 grams of carbohydrate (124 calories) and 15 grams of fat (135 calories), which yield a sum (271 calories) that is close to the listed caloric content of the food.

In previous installments, I've explained how it is important to allot your calories in an appropriate manner once you determine how many you'll be ingesting. One reason is to make sure you get the right amount of each macronutrient. According to USDA recommendations, 10-35 percent of your total energy intake should come from protein, which means that the donut diet wouldn't cut it because it doesn't deliver a sufficient amount (12/261 = 5%). Protein is required for tissue repair and to make enzymes and hormones that are important for healthy function, so insufficient intake has negative repercussions. What is more, people who exercise regularly require a greater amount as do pregnant and nursing women and children and adolescents who are still growing. The long-standing belief is that we should consume 0.8 grams of protein for every kilogram of bodyweight; however, the current line of thought is that we need more (for example, as much as two grams per kilogram for those who perform vigorous endurance exercise). This means that the donut diet also fails according to this criterion because a 150-lb person would require at least 55 grams per day and as many as 136. Eight donuts would only provide 24.

Protein is under represented in the donut diet, which means that another macronutrient must be present in excess. Not surprisingly, the culprit is fat. Fat contributes 48 percent of the energy in a donut (125/261), which is significantly more than the high end of the recommended range (20-35). Of course, this doesn't mean that you can never eat a donut because in a well-rounded eating regimen that comprises many different foods each day, you can offset that excess by including another food that contributes less than the low end of the range. But it is also important to note the type of fat that you are ingesting. The USDA suggests that saturated fat should be limited to less than 10 percent of total calories and trans fat should be restricted to as little as possible. Similarly, it's important to consider the type of carbohydrate, which the donut does provide in an appropriate amount (124/261 = 48%; recommended range: 45-65%).

This article was originally published in New Living Magazine, which can be accessed on-line at www.newliving.com.





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