America the Butterball
My fellow Americans, we’re fat. But we need not be; the solution is simple. I have discovered the perfect diet.
That America is suffering an epidemic of obesity is well established. Nearly one in every three kids under the age of 18 is seriously overweight. Associated with this weight gain are increased risks in adulthood for joint problems, angina, high blood pressure, heart attacks, strokes, type 2 diabetes, and ultimately premature death. Health experts estimate that treating adult obesity-related ailments cost the American economy nearly $150 billion in 2009. We are awash in a sea of greasy fast food and sweet soft drinks. Junk foods oozing with processed sugars, trans-fats and excess salt are ubiquitous, available anywhere, everywhere, all the time.
Many complicated factors contribute to the epidemic beyond the most obvious, and most important, baseline of personal responsibility. Ill-conceived public policies, advertisements that target impressionable children, increasingly sedentary lifestyles, and the allure of convenience in the face of a busy day all donate to the cause.
While our growing girth is therefore no surprise in a culture defined by Golden Arches, by no means should obesity be seen as inevitable. To see why, we have to go back to basics to understand a few simple facts of biology, and of metabolism more specifically. Class, open your text!
The Lowly Calorie
Everybody talks about calories but I can think of no subject more prone to disinformation, misunderstanding and misconception. No common word in our vocabulary has been more corrupted by pseudoscience and misguided beliefs. We must clean up this mess before discussing anything else related to weight gain. Fortunately, that is easily done.
A calorie is a unit of energy. A calorie is defined as the amount of energy required to raise the temperature of one gram of water by one degree.
I have to say the following to protect myself from attack by science nerds. All others, feel free to skip to the next paragraph to continue my point. Yes, I mean degrees Celsius, at one atmosphere. I mean here the gram calorie (or small calorie) to distinguish from the original definition based on the kilogram. To confuse matters, when discussing food energy, the common unit is actually the kilocalorie, but the prefix is almost always dropped, so people say calorie when meaning kilocalorie. Also, the amount of energy required to raise water temperature depends on the starting temperature, making the definition vulnerable to variability. For the sake of simplicity, I mean calorie, not kilocalorie, and I assume the calorie is equal to 4.2 Joules.
Nowhere in the definition of a calorie is there any mention of the source of fuel needed to raise the temperature of one gram of water one degree. To heat the water you can burn coal, put fire to banana peels or use a BIC lighter. The only measure is the total energy necessary to raise the water temperature by the specified amount. Burning one calorie is burning one calorie no matter what is being consumed by the fire.
Therefore, we come to an important conclusion: one calorie of carbohydrate is exactly equal to one calorie from fiber, which is precisely equal to one calorie from saturated fat. One calorie of fruit equals one calorie from a fudge bar. As a unit of energy a calorie remains constant, always, across all foods.
Of course, if you consume one pound of fudge you will consume more calories than if you eat one pound of broccoli – because calories are more densely packed into the sweet. But if you take a small nibble of fudge equivalent to one calorie or a big bite of broccoli equal to one calorie, you will have consumed one calorie whether that came from the vegetable or confection.
I pound home this point because the idea is so pervasively misunderstood, and then any discussion of weight gain goes downhill from there. Understand this fundamental point: when discussing weight loss (ignoring for the moment nutritional health), and weight loss alone, the source of calories you consume does not matter. The only thing that matters (looking at weight loss only) is total calories you eat, regardless of where they come from, compared to total calories you burn.
If your energy intake (food calories) equals the energy (calories) you burn up by living, breathing, working, and sleeping, you will gain no weight. If energy in exceeds energy out, you gain weight, with the excess stored as fat. If energy in is less than energy out, you lose weight by consuming previously stored fat. There is no other formula. Nothing else matters concerning weight loss but the balance between the total calories you take in and total calories you burn.
I will lose weight if all I eat is 900 calories per day of rich dark chocolate fudge. I would not be healthy because I would not be getting the necessary vitamins, minerals, fiber and other essential nutrients for a balanced diet, but I would lose weight. And I would lose weight at exactly the same rate if I ate only 900 calories per day of Red Delicious apples. Or 900 calories of all protein; or 900 calories of simple carbohydrates; or 900 calories of complex carbohydrates; or 900 calories of anything edible. Because 900 calories is always 900 calories, no matter the source. Energy in versus energy out; nothing else matters in determining weight gain or loss. Nothing. That is a fact of biology and physics.
For us to make it through a day, we must chemically convert energy stored in food into useful energy we can tap for vital functions like mowing the lawn, mating and watching reality T.V. Living things have the ability to take matter and energy from their environment and change it from one form to another. That process of conversion is metabolism. Plants convert sunlight and carbon dioxide to cellulose and sugars. Herbivores convert plants and their sugars to meat and movement through the process of digestion. Carnivores do the same favor to herbivores. That is a good story, with a happy ending if you are the carnivore.
More specifically, inside our cells aerobic respiration involves combining glucose with oxygen, which yields energy plus carbon dioxide and water as waste. For those who enjoy symmetry, this is the exact reverse of the reaction that takes place with photosynthesis, a process in which plants use the energy of sunlight to combine carbon dioxide and water into sugar and oxygen.
We usually think of respiration as breathing in and out. But biologists also speak of a different type, cellular respiration. Cellular respiration is the process of converting food energy (calories!) into a specific form of energy that your cells can use (called ATP, which like any good fire, needs oxygen to burn). Let’s see how this works, starting by reaching out for that big bowl of peanuts sitting on the coffee table.
Grab some goobers, chew and swallow. We’re on our way. What happens next is that digestion breaks down food (catabolism) into molecules such as glucose and simple carbohydrates. Cellular respiration gets its fuel from this digestive process, taking the products of digestion and converting them into ATP. Some of that ATP is then used to make new molecules (anabolism) that you need to live. Here is an easy way to look at this: you eat in order to convert food fuel (calories) into ATP through catabolism and cellular respiration. You breathe to give your cells the oxygen they need to burn ATP to make your skin and bone through anabolism, and to power all the other essential functions of life.
So through metabolism (the processes of cellular respiration, catabolism, and anabolism), your body converts the calories (energy) in the food you eat into an energy source it can burn, ATP, to make the molecules you need to live, and to power the muscles you need to move and breath, which brings in the oxygen that allows you to burn ATP made from the food you gathered and ate…and so the cycle continues.
Weight Gain or Loss
The precise biochemical pathways your body uses to break down food molecules and rebuild them into the molecules you need to live are outrageously complicated, intricately choreographed, awesomely fine-tuned feedback loops. Many of you will recall from early college days the dreadful task of memorizing the citric acid cycle (more famously known as the Krebs cycle), integral to carbohydrate metabolism. Fats, proteins and carbohydrates all have unique catabolic pathways. But do not let scientists or nutritionists bamboozle you with these complexities; they are not relevant to weight loss, regardless of how impressive we might sound when talking about acetyl coenzyme A.
So why the biology lesson? Note that in describing how your body converts food calories to ATP, no mention was made of where those calories came from. Because ATP could care less if the calorie came from fudge or fruit. It takes so many units of energy (calories) to create an ATP molecule, whether those calories come from organic wheat or gooey processed sugar. So let me emphasize here again, when discussing weight loss alone, the source of calories you consume does not matter. We only care about calories in versus calories out.
Think of your body as a machine, albeit one that is extraordinarily complex. Like any machine we require energy to run. Let’s say you require 2500 calories per day to generate enough ATP to fuel your activities and to make all the supporting materials your body needs. Eat 2500 calories per day and your weight will remain unchanged. Chow down on 4000 calories per day, and 2500 will be used to support all of your biological needs, and much of the remaining excess 1500 calories will be converted to adipose tissue as storage for future use. You get fat. Munch only enough to bring in 1000 calories a day, and your body will convert the energy stored in your fat reserves to manufacture enough ATP to fill the ATP deficit caused by the missing 1500 calories. You lose weight.
Losing weight is not equivalent to being healthy. Nobody would argue that eating an exclusive diet of 900 calories of dark fudge daily would be too bright, even if highly effective in shedding pounds. To remain robust we must eat a balanced diet of carbohydrates, proteins, fats, fiber, vitamins, and other essential nutrients. Now, finally, the source of our calories matters, and critically so. Not for losing weight, but to determine how healthy we will be in our weight reduction.
Every diet you have ever heard of is nothing but a scheme to fool you into eating fewer calories. Some do so with an eye toward nutritional balance, while others are less responsible. Diets are simply disguised behavioral modification programs to trick you into putting less food, and less densely-caloric food, in your mouth. Some are effective, and that is just fine. But do not believe for a second that the diet is doing anything but helping you reduce your daily caloric intake. Exercise helps of course because the weight equation has two sides; calories in (eating) and calories out (activity). If you increase the number of calories you burn through exercise (one side of that equation), you can eat more (the other side of the equation) to equal that increased caloric burn.
Beware of any diet that emphasizes one food group over another. We need them all to maintain healthy balance. Our bodies need carbs, fats, proteins, fiber, minerals, and vitamins, but we need them in balance and in moderation.
We hear claims that certain foods “increase metabolism” or that some special berry helps us process food more effectively. Or certain mystery proteins change the balance between anabolism and catabolism. All hogwash, but let’s say for a moment that such assertions were true. So what? The formula that calories in must equal calories out does not change. If something increases your metabolism, great, you can eat just that much more to balance the equation. But the equation must still be balanced. If some food helps you process food more efficiently, wonderful, but the formula remains the same. If you eat more calories than you burn, you will gain weight.
Another ridiculous claim is that the timing of our meals matters. We are told not to eat before going to bed, or that breakfast is the most important meal. Or it is better to eat a number of small meals compared to few larger ones. Nonsense all. The only thing that counts over any 24 hour period is the balance between the total calories you ate versus the total calories you burned.
So, finally, you can throw out each and every diet book in your kitchen. Here is the only diet advice you will ever need: eat less, eat well and exercise. End of story.
There is nothing else, no magic formula, no easy way, no secret ingredient, no special foods, no miracle diet. If you are not willing to eat less, eat well and exercise, you are not willing to lose weight and maintain nutritional balance. It really is that simple – and that difficult. You control calories in by what you put in your mouth; you control calories out by how active you are. This is an immutable reality. No diet in the world will help you unless that diet is just an excuse to eat less, eat well and exercise.
We do our entire population an enormous disservice anytime we shy away from this simple advice. Anything else is a scam. We must take personal responsibility for our own bodies. Except in the most extreme and extraordinarily rare case, any human that eats less, eats well and exercises will lose weight. If circumstances prevent exercise, then eating even less is necessary. This is reality. This is life. No amount of wishing for a miracle will make one appear.
The real miracle here is we each have within us the power to do better; we just have to want to do better bad enough. We are responsible for the outcome, for better or worse. Own it. Embrace it.
So eat less, eat well and exercise. You have no other option. You can do nothing else if you want to lose weight.