Whether you can lose weight just by cutting calories depends. We’re often told that our diets comprise anywhere from 60-80% of our ability to lose or maintain weight as well as our overall fitness. If we eat a lot of fat and simple carbohydrates, for instance, we often eventually pay a price. So there is a relationship between diet and body composition, but whether or not just cutting calories will be enough for you to lose weight is dependent on a number of factors, some of which you can manage, such as various aspects of your diet, and others you can’t, such as your genetics.
Our diets should contain six essential macro and micro nutrients. Each day, we have to feed our bodies carbohydrates, fats, proteins, water, vitamins and minerals. While carbohydrates, fats, proteins, and water are macronutrients, vitamins and minerals are micronutrients. Micronutrients are only needed in small amounts. Nevertheless, they are essential for normal metabolism, electrolyte balance, and growth.
Macronutrients supply us with energy. Energy is measured in calories and is essential for the body to grow, repair old tissues, such as muscles, and develop new tissues, conduct nerve impulses and regulate body temperature.
All fat and all carbohydrates are not bad for us. When eaten in moderation, good fats, the monounsaturated and polyunsaturated fats, like the kind found in avocados, salmon, walnuts, sardines, and mackerel, helps to lower our low-density lipoprotein (LDL) (bad type of cholesterol) and overall cholesterol levels and to lower our chances of getting heart disease and colon cancer, and they keep us satiated. Many of the foods mentioned above contain omega-3 fatty acids. Trans fats, and other manmade fats, are the ones that clog our arteries, raise our blood pressures, LDL cholesterol and our disease risk. Saturated fat, animal fat, contributes to heart disease and raise LDL cholesterol, but, contrary to belief, it cannot harden inside a 98.6 degree body, and it is believed that it also contributes to good or HDL cholesterol.
Simple carbohydrates are sugars, like the kind found in candy, soda, and fruit (yes, fruit) and it adds very little, but calories to our diets. Fruit does contain unhealthy sugar, but it can be healthy for most people if eaten in small amounts. For one thing, many fruits contain a high amount of fiber or micronutrients, such as Vitamins C and E or the minerals, zinc or potassium, for instance. But most simple carbohydrates, like many candies, tend to be devoid of enough nutrients to justify their calorie contents. They also activate the “reward circuit” of our brains, tricking the pleasure centers of our brains into addiction. That creates a vicious cycle that can easily lead to weight gain. Carbohydrates, however, complex, fibrous carbohydrates are needed in our diets, because they, like monounsaturated and polyunsaturated fats lower our LDL and overall cholesterol and our risk of colon cancer and can make us feel full longer. That helps us to manage our appetites.
In terms of satiation, fat holds us the longest, followed by protein. Carbohydrates, largely because of the simple carbohydrates, come in last. The reason why eating a lot of fats and carbohydrates, for instance, is not encouraged as a weight loss method is simple: You can get too much of a good thing. Can you say, diarrhea, for instance. Fat also contains 9 calories per gram while both carbohydrates and proteins contain only 4 calories per gram. So although some fats can be good for you, fat is also highly caloric.
The USDA recommends that we get about 20-35% of our calories each day from fat, 45-65% from carbohydrates, 10-35% from protein. The reason why there is a range is because our dietary needs vary depending on the type of activity in which we are normally engaged. A bodybuilder needs a different breakdown of macronutrients (and possibly micronutrients) than a distance runner does. The bodybuilder needs a high amount of protein, a medium amount of carbohydrates, and a low amount of fats. Endurance athletes (runners, bikers, swimmers) need a high amount of carbohydrates, a medium amount of protein and a low amount of fat. Most people need a higher amount of fat than both bodybuilders and endurance athletes, although no one needs a high amount.
Almost all hormones – insulin, testosterone, estrogen, progesterone, hemoglobin (blood protein) – is composed of protein. And enzymes are. Enzymes are involved in homeostasis and they help to stabilize every chemical reaction in our bodies (regulate our appetites, thyroid activity, bowels, muscle contractions).
To lose weight, I’ve seen various recommendations, such as carbohydrates, proteins and fats should be eaten in a ratio of 50%, 30% and 20%. ChooseMyPlate.gov also suggests that half of the grains we eat each day, which are usually carbohydrates, should be whole grains (whole wheat, quinoa, barley, oats). Because we digest whole grains slowly (they take more effort for our bodies to breakdown), they do not spike our blood sugar levels. Spiking causes blood sugar levels to rise and then fall quickly. Low blood sugar causes hunger. Simple carbohydrates cause a sudden spike in blood sugar, then a sudden drop.
To find the right combination of macro and micro nutrients for you, it’s best to consult a registered dietitian. At the very least, visit ChooseMyPlate.gov which is the USDA web site where you can get an idea about what the dietary recommendations are for you. Yes, for you. Just like everything else, when it comes to fitness, diet also has to be individualized. You can meet the USDA recommendations while customizing meals and meal times to satisfy your tastes and schedule. Eating small frequent meals works for some people, but not for all. It never worked for me. I must have one fairly large meal per day to feel like I’ve eaten, to feel satiated. I’ve found that I can put together a satisfying and large breakfast for about 400-450 calories. So if you find that one recommendation does not work, try another. The right way is the way that works for you.
This is what I’ve found, diet is a very important component of weight loss, but its value, as the most important component, decreases as we age. Here’s an example. When I was 28 years old, I went on a Haagen-Dazs diet and gained about twenty pounds in a few months (I was already about 15 pounds overweight when I gained that weight). I vowed to take it back off, and I did without much hardship.
I cut 500 calories per day from my diet and walked around San Francisco’s Embarcadero Center for about a half hour each day during my lunch hour from Monday through Friday. I dropped 25 pounds in about two and a half months.
Fast forward nearly 25 years. Over the years, I had gained the 25 pounds back and then some. But a strange thing happened when I tried to use my old method of weight loss. I couldn’t. Doing what I did in the past was against my dietitian’s advice. Women need at least 1,200 calories per day, I was told. When less than 1,200 calories are consumed, we have a difficult time getting enough micronutrients.
When I was 28 years old, I had a resting metabolic rate (RMR) of about 1,850. Resting metabolic rate is a measure of how many calories we burn while at rest (our lungs, hearts, livers and kidneys burn calories). As a 50-year-old, I had a RMR of about 1,350, and that was likely because I was exercising. Exercise raises metabolism. Other women my age and size, who are fairly sedentary, have RMRs of about 1,100. So I had an RMR that burned an amount of calories that was already deemed to be below the amount required for health. Meaning at age 50, I had to exercise to keep from gaining weight when eating the minimum recommended number of calories. While going over the number of calories we need by just 50 to 100 calories per day does not seem like a lot, over the course of one year that number of calories adds up to a 5-10 pound weight gain. One pound is equal to 3,500 calories.
The point is that I couldn’t cut 500 calories from my diet to lose weight. I had to exercise and exercise a lot. What that says is that exercise plays a bigger role in overall fitness as we age. Getting in the habit when we’re younger wouldn’t hurt. Plus, see how much more difficult it is to lose weight as we age? We still need to watch our diets, partly because we have to do more than younger people to burn calories and partly because we are what we eat. We need the correct balance of macro and micro nutrients, because they support life.
Our metabolisms decrease as we age, partly because muscle loss accelerates, and muscle is more metabolically active than fat. But exactly what causes the breakdown is a mystery. Does our ability to process macro and micro nutrients become less efficient and, therefore, our bodies become less able to regulate hormones and enzymes? No one knows for sure yet. That answer may be the fountain of youth.