Input Output

Keeping in mind that what you burn can be expressed simply as a number of calories, it's enlightening to look at what goes in and what comes out in somewhat more detail than you might have ever contemplated.

Consider this view of human as rubber bag presented at a NASA conference on the exploration of Mars.1

'"Mars Mission Life Support," by Dr. Penelope J. Boston, National Center for Atmospheric Research, in "The NASA Mars Conference," Duke B. Reiber, ed., Volume 71, Science and Technology Series, American Astronautical Society, San Diego, 1988.

Typical Human Mass Throughput Pounds/Day

From this all-inclusive perspective, which accounts for the oxygen in the air we breathe, moisture lost through the skin, and water generated by the reactions that break down the food we eat and reassemble it into the cells of our body, a human being, the "beauty of the world! the paragon of animals!" resembles a water pump more than the most intelligent known life form in the universe.

This is important information, not just to Mars mission planners or inveterate collectors of fascinating details, but to anybody interested in controlling their weight. Explained here are the reasons so many people misunderstand how their bodies react when they're trying to lose weight, why so many people become frustrated and abandon sincerely undertaken efforts to control their weight.

It's the water. On a day to day basis, the water you consume, whether directly in beverages or as part of the foods you eat, and the water you excrete in your various excursions to the hydraulic accommodations, dwarfs the weight of the food you eat and the solid waste you dispose of. To this extent: 68% of the mass you consume every day is water, and 81% of what goes out is likewise water. Startling, until you recall the human body is, by weight, about three quarters water. Average the percentages of water in and water out, and you get. . . 75%: three quarters.

Every day your body ingests plenty of water and disposes of even more. Most of the changes in weight you see from day to day on a scale reflect nothing more than how much water is in the rubber bag at the moment. Consider: if you pig out to the extent of three slices of pizza before bedtime every night for a whole month, you'll gain about four pounds as the lingering souvenir of your month of wild abandon. Yet even that extreme weight gain is less than half your daily intake and disposal of water.

Most of the changes in weight you see have nothing to do with how many calories you're eating or burning. Instead, all you're seeing is how many pounds of water happen to be inside the rubber bag at the moment. How many bleak mornings of dark despair endured by forlorn dieters who indulged in a bowl of salted popcorn at midnight then slaked their thirst with a large glass of water in the middle of the night, would have been taken in stride had only the implications of human being as water pump been fully comprehended? Food fads

Attempting, for four decades or more, to remain rooted in the tenuous and shifting soil of reality tends to make one skeptical of suggestions of grand conspiracies by insiders pulling the strings that run the world. And yet, and yet. . . .

It seems like every few months a new "scientific discovery" about food and health bursts upon the scene. How far do you go back? Remember...

  • 100% polyunsaturated fat!
  • With the iron that women need!
  • High-fibre!
  • Enriched with zinc!
  • More calcium than the leading brand!
  • Now with oat bran for your heart!

Fuzzy thinking

First, a legitimate researcher publishes a study in the New England Journal of Medicine that claims, heavily hedged and based on largely statistical evidence, to demonstrate a connection between a certain dietary component and some aspect of health, for example, a particular kind of fibre and serum cholesterol levels. That night, the evening news trumpets, "Researchers at the University of Sausalito have discovered a connection between peach fuzz and heart disease. In a study of 100 peach pickers and packers...". Before you know it, the Sunday supplement's bulging with recipes for peach pie with fuzzy crust.

Meanwhile, the advertising engine is coming up to speed. Full page ads sponsored by the Georgia Peach Association proclaim, "Look for 'Fresh Georgia Peaches' on the bag. And remember, only Georgia peaches have 25% more fuzz". Oat-this and oat-that breakfast cereals begin to vanish from the supermarket, displaced by the arrival of Peachies, Fuzz-chex, and Teenage Mutant Fuzzy Ninja Turtles. Soon, the whole supermarket looks like it's been sprayed with minoxodil. Whole grain cookies enriched with peach fuzz. Fuzz-tab supplements. Fuzzy toothpaste. "Fizzy fuzz" peach champagne.

Now everybody else tries to jump on the bandwagon. The Soybean Institute launches a new promotion to remind people that soybeans are the "hairy legume." Cheese-makers remind consumers "Cheese—so good for you it grows its own fuzz in the fridge." "The Fuzzy Way To Health," "Dr. Harry's Fuzz Diet," and "The Plantation Peach-Fuzz Cookbook" contend for space in the bookstore window, and their authors make the rounds of the talk shows.

The silliness builds to a crescendo of absurdity, around which time the medical journals start to publish papers such as "Peach Fuzz: No More Effective Than Sawdust" and "No Fuzz-Cholesterol Link In Rats." As the wave begins to recede, another article is published, "Possible Correlation Between Sesame Seed In Diet and Immune System Performance." And away we go again.

Food and fact

The rubber bag view of the body and considering only the calorie content of food is obviously oversimplified. There is a difference between eating a varied diet and chowing down on a cup of lard and sugar once a day. Programmers know this instinctively: they balance their daily menu among the four major food groups: caffeine, sugar, grease, and salt.

In reality, food satisfies two distinct needs of the body. The first is for energy. A substantial amount of energy is needed just to maintain a constant body temperature and keep the heart, lungs, and the rest of the body's mechanisms running. The energy consumed by a human body is comparable to a 100 watt light bulb. Food also supplies the raw materials the body uses to manufacture all the chemicals it needs, including those needed to build new cells.

From the standpoint of energy, almost any food will do; you can assume that all foods with the same calorie content are interchangeable. Eating the right mix of food only becomes important when you consider food as raw material. For the most part the body breaks food down into small molecules composed of carbon, hydrogen, oxygen, and nitrogen and then manufactures what it needs from these building blocks. However, certain structures in the body require other constituents. For example, iron is needed to form the hemoglobin that carries oxygen in red blood cells, and calcium forms the matrix that strengthens bones. In addition, there are a number of complicated organic molecules our bodies require but cannot, for one reason or another, manufacture. These raw materials, minerals and vitamins, must be furnished or else the body begins to develop deficiency diseases such as scurvy and rickets.

If you eat a reasonable selection of food, varied within each meal as well as from meal to meal, it's extremely unlikely you'll come up short one of these crucial sub stances. (Vegetarians have to be careful, as some nutrients abundant in meat are present only in a limited number of plant foods: these considerations are discussed in detail in numerous books describing vegetarian diets, and I won't go into them here.)

The reason we focus entirely on calories when talking about weight control is that the energy-producing aspect of food is what determines whether you gain or lose weight. Unless your diet is wildly out of whack, which particular foods you eat has very little effect on your weight, compared to the calorie total. To lose weight, you have to eat less. When you eat less, you'll not only be putting less energy in the rubber bag, but also supplying less of the raw materials the body needs. It is, therefore, important to maintain a balanced diet as you lose weight.

Be reasonable. I think the main reason so many diet books are packed with information about food, special recipes, and the like is that it's a useful way to pad out the essential message of a diet book, "eat less food," into something thick enough to be visible on the shelf. As long as you vary what you eat and choose your foods from all around the supermarket, the probability you'll develop a deficiency disease whilst dieting is extremely remote. If you supplement your food with a multivitamin every day (any one that provides 100% or more of the RDA of the big name nutrients is fine), you have even less cause for concern.

If you adopt the "Clam juice and brown rice quick-loss diet" from the supermarket tabloid, good luck. At least eat some peach fuzz along with it.

Gaining Weight 101

Gaining Weight 101

Find out why long exhausting workouts may do more harm than good. Most of the body-building workout and diet regimens out there are designed for the guys that gain muscle and fat easily. They focus on eating less and working out more in order to cut the excess fat from their bodies while adding needed muscle tone.

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