Chapter One
The Truth about Carbs, Fats and Protein
 
It’s just about impossible to live in this country and not know that we are in the midst of an “obesity epidemic.” If you watch television, listen to the radio, read the newspaper or simply notice the magazine headlines at the supermarket checkout, you can’t help but be aware that nearly 56 percent of Canadians are overweight and that our obesity rate has doubled over the past twenty years. Everyone seems to have an explanation for our collective weight crisis: some hold the fast-food industry responsible; others blame our sedentary lifestyle. Some maintain we are eating too much fat; others say we are eating too many carbohydrates. So what’s the truth?
 
Well, all of these reasons are part of the answer. But if you reduce the problem to its physiological cause, it’s actually quite simple: we’re consuming more calories than we’re expending, and the resulting surplus is stored around our waists, hips and thighs as fat. There’s no mystery here. But to understand why we are consuming more calories, we need to get back to basics and look at the three fundamental elements of our diet: carbohydrates, fats and protein. We need to understand the role these components play in the digestive system and how they work together—whether we’re in the process of getting fat or thin.
 
We’ll start with carbohydrates, since the popularity of low-carbohydrate diets like the Atkins program has made them a hot topic and given them a bad rap. Carbohydrates have been so much in the news over the past few years that a new word—“carbs”—has entered the language. Though they’ve been blamed for all our weight problems, their role in weight control has really been misunderstood.
 
Carbohydrates
Carbohydrates are a necessary part of a healthy diet. They are rich in fibre, vitamins and minerals, including antioxidants, which we now know play an important role in the prevention of heart disease and cancer. Carbohydrates are also the primary source of energy for our bodies. They are found in grains, vegetables, fruits, legumes (beans) and dairy products.
 
Here is how carbs work: when you eat an orange or a bagel, your body digests the carbohydrates in the food and turns them into glucose, which provides you with energy. The glucose dissolves in your bloodstream and then travels to the parts of your body that use energy, such as your muscles and brain. So carbs are critical to everyone’s health. When managing weight, however, it is important to realize that not all carbs are created equal.
 
Some carbohydrates break down into glucose in the digestive system at a slow and steady rate, gradually releasing their nutrients and keeping us feeling full and satisfied. Others break down rapidly, spiking our glucose levels and then disappearing quickly, leaving us feeling hungry again. For example, cornflakes and old-fashioned, large-flake oatmeal are both carbohydrates, but we all know the difference between eating a bowl of oatmeal for breakfast and eating a bowl of cornflakes. The oatmeal stays with you—it “sticks to your ribs,” as my mother used to say—whereas your stomach starts rumbling an hour after eating the cornflakes, pushing you toward your next snack or meal. Throughout the course of a day, if you are eating carbs that break down rapidly, like cornflakes, as opposed to those that break down slowly, you will be eating more and, as a result, will begin to put on weight. If, however, you start eating carbs that break down slowly, like old-fashioned oatmeal, you will eat less and begin to lose weight. Selecting the right type of carb is key to achieving your optimum energy and weight. But how do you know which carbohydrate is the right type and which isn’t?
 
Well, the first clue is the amount of processing that the food has undergone. The more a food is processed beyond its natural, fibrous state, the less processing your body has to do to digest it. The quicker you digest the food, the sooner you feel hungry again. This helps explain why the number of Canadian adults who are overweight has surged over the last fifty years. A hundred years ago, most of the food people ate came straight from the farm to the dinner table. Lack of refrigeration and scant knowledge of food chemistry meant that most food remained in its original state. However, advances in science, along with the migration of many women out of the kitchen and into the workforce, led to a revolution in prepared foods geared to speed and simplicity of preparation. The giant food companies—Kraft, Kellogg’s, Del Monte, Nestlé, etc.—were born. We happily began spending more money for the convenience of prepared, processed, packaged, canned, frozen and bottled food. The Kraft Dinner era had begun.
 
It was during this period that the miller’s traditional wind and water mills were replaced with high-speed steel rolling mills, which stripped away most of the key nutrients, including the bran, fibre and wheat germ (which could spoil), to produce a talcum-like powder: today’s white flour. This fine white flour is the basic ingredient for most of our breads and cereals, as well as for baked goods and snacks such as cookies, muffins, crackers and pretzels. Walk through any supermarket and you will be surrounded by towering stacks of these flour-based processed products. And we’re eating more and more of these foods; over the past three decades our consumption of grain has increased by 50 percent. Our bodies are paying the price for this radical change in eating habits.
 
The second clue in determining whether a carbohydrate is the right type is the amount of fibre it contains. Fibre, in simple terms, provides low-calorie filler. It does double duty, in fact: it literally fills up your stomach, so you feel satiated; and your body takes much longer to break it down, so it stays with you longer and slows the digestive process. There are two forms of fibre: soluble and insoluble. Soluble fibre is found in carbs such as oatmeal, beans, barley and citrus fruits, and has been shown to lower blood cholesterol levels. Insoluble fibre is important for normal bowel function and is typically found in whole wheat breads and cereals, and most vegetables.
 
There are two other important components that inhibit the rapid breakdown of food in our digestive system, and they are fats and protein. Let’s look at fats first.
 
Fats
Fat, like fibre, acts as a brake in the digestive process. When combined with other foods, fat becomes a barrier to digestive juices. It also signals the brain that you are satisfied and do not require more food. Does this mean that we should eat all the fat we want? Definitely not!
 
Though fat is essential for a nutritious diet, containing various key elements that are crucial to the digestive process, cell development and overall health, it also contains twice the number of calories per gram as carbohydrates and protein. If you decide to “just add peanut butter” to your otherwise disciplined regime, it doesn’t take much of it—two tablespoons—to turbo-charge your total calorie count. As well, once you eat fat, your body is a genius at hanging onto it and refusing to let it go. This occurs because fat is how the body stores reserve supplies of energy, usually around the waist, hips and thighs. Fat is money in the bank as far as the body is concerned—a rainy-day investment for when you have to call up extra energy. This clever system originally helped our ancestors survive during periods of famine. The problem today is that we don’t live with cycles of feast and famine—it’s more like feast, and then feast again! But the body’s eagerness for fat continues, along with its reluctance to give it up.
 
This is why losing weight is so difficult: your body does everything it can to persuade you to eat more fat. How? Through fat’s capacity to make things taste good. So it’s not just you who thinks that juicy steaks, chocolate cake and rich ice cream taste better than a bean sprout. That’s the fat content of cake and steak talking.
 
Sorry to say, there’s no getting around it: if you want to lose weight, you have to watch your fat consumption. In addition, you need to be concerned about the type of fats you eat; many fats are harmful to your health. There are four types of fat: the best, the good, the bad and the really ugly. The “really ugly” fats are potentially the most dangerous, and they lurk in many of our most popular snack foods. They are vegetable oils that have been heat-treated to make them thicken—the trans fats you’ve been hearing so much about in the media. They raise the amount of LDL, or bad, cholesterol in our bodies while lowering the amount of HDL, or good, cholesterol, which protects us from heart disease. As a result, they boost our cholesterol levels, which thickens our arteries and causes heart attack and stroke. So avoid using trans fats, such as vegetable shortening and hard margarine, and avoid packaged snack foods, baked goods, crackers and cereals that contain them. (You can spot them by checking labels for “hydrogenated” or “partially hydrogenated” oils.)
 
The “bad” fats are called saturated fats and almost always come from animal sources. Butter, cheese and meat are all high in saturated fats. There are a couple of others you should be aware of too: coconut oil and palm oil are two vegetable oils that are saturated and, because they are cheap, they are used in many snack foods, especially cookies. Saturated fats, such as butter or cheese, are solid at room temperature. They elevate your risk of heart disease and Alzheimer’s. The evidence is also growing that many cancers, including colon, prostate and breast cancer, are associated with diets high in saturated fats.
 
The “good” fats are the polyunsaturated and monounsaturated ones, which are cholesterol free. Most vegetable oils, such as corn and sunflower, fall into this category. What you really should be eating, however, are the “best” fats, the monounsaturated fats, which actually promote good health. These are the fats found in olives, almonds, and canola and olive oils. Monounsaturated fats have a beneficial effect on cholesterol and are good for your heart. This is one reason the incidence of heart disease is low in Mediterranean countries, where olive oil is a staple. Although fancy olive oil is expensive, you can enjoy the same health benefits from less costly supermarket brands.
 
Another highly beneficial oil that falls into the “best” category is omega-3, a fatty acid found in deep-sea fish, such as salmon, mackerel, albacore tuna and herring, as well as in lake trout, walnuts, and flaxseed and canola oils. Some brands of eggs and liquid eggs also contain omega-3, which can help lower cholesterol and protect cardiovascular health.
 
So the “best” and “good” fats are an important part of a healthy diet and also help slow digestion. Still, they’re fat and they pack a lot of calories. Over twice as many calories per gram as carbohydrates or protein. We have to be careful, then, to limit our intake of these polyunsaturated and monounsaturated fats when trying to lose weight.
 
Since protein also acts as a brake in the digestive process, let’s look at it in more detail.
 
Protein
Protein is an absolutely essential part of your diet. In fact, you are already half protein: 50 percent of your dry body weight is made up of muscles, organs, skin and hair, all forms of protein. We need this element to build and repair body tissues, and it figures in nearly all metabolic reactions. Protein is also a critical brain food, providing amino acids for the neurotransmitters that relay messages to the brain. This is why it’s not a good idea to skip breakfast on the morning of a big meeting or exam. The “brain fog” people experience on some diets is likely the result of diminished protein. Protein is literally food for thought.
 
The main sources of dietary protein come from animals: meat, seafood, dairy and eggs. Vegetable sources include beans and soy-based products such as tofu. Unfortunately, protein sources such as red meat and full-fat dairy products are also high in “bad,” or saturated, fats, which are harmful to your health. It is important that we get our protein from sources that are low in saturated fats, such as lean meats, skinless poultry, seafood, low-fat dairy products, cholesterol-reduced liquid eggs, and tofu and other soy products. One exceptional source of protein is the humble bean. Beans are a perfect food, really: they’re high in protein and fibre, and low in saturated fat. No wonder so many of the world’s cuisines have found myriad wonderful ways to cook beans. North Americans need to become more bean savvy. Nuts are another excellent source of protein and are relatively low in fat—as long as you don’t eat a whole bowlful.
 
Protein is much more effective than carbohydrates or fat at satisfying hunger. It will make you feel fuller longer, which is why you should try to incorporate some protein into every meal and snack. This will help keep you on the ball and feeling satisfied.
 
Now that we know how carbohydrates, fats and protein work in the digestive system, let’s use the science to discover how to take off the extra pounds.
 
TO SUM UP
• Eat carbohydrates that have not been highly processed and that do not contain highly processed ingredients.
• Eat less fat overall and look for low-fat alternatives to your current food choices.
• Eat only monounsaturated and polyunsaturated fats.
• Include some protein, preferably from both animal and vegetable sources.