Table 2: Macronutrient Consumption of Successful Weight Losers
|
% Fat |
% Carbohydrate |
% Protein |
|
|
24 (women) (108) |
56 |
20 |
|
|
24 (109) |
56 |
19 |
|
|
23 (110) |
58 |
19 |
|
|
26 (111) |
55 |
19 |
|
|
24 (112) |
56 |
19 |
|
|
29 (113) |
49 |
22 |
|
|
Average |
25 |
55 |
20 |
As you can see from the table, NWCR members eat a low-fat, high-carbohydrate diet. They consume an average of 25 percent of their calories from fat, 55 percent from carbohydrate, and 20 percent from protein, with no difference in the macronutrient percentages between women and men. Age also doesn’t make a difference in the macronutrient composition of the diet, as young adults (eighteen to thirty-five years old) and older adults (thirty-six to fifty years old) consume a similar percentage of calories from fat (as well as from alcohol, sugar-sweetened beverages, and total calories).114
Historically, fat has taken a lot of the blame for making people fat. Indeed, the data from the NWCR and other studies have shown that the amount of dietary fat and an increase in the percentage of calories from fat from one year to the next are both significant predictors of weight regain. However, while it’s easy to think that if you eat fat, you’ll get fat, fat itself doesn’t make you fat. The main reason for a low-fat diet—and the presumed reason why the NWCR members control their fat intake—is because of fat’s high caloric density rather than because it’s fat per se. At nine calories per gram, fat provides a concentrated calorie source to give you energy. Fat is more than twice as calorically dense as carbohydrate and protein, both of which have four calories per gram.
Fat is actually a very important part of your diet. You can blame your brain. Your brain is an expensive organ to maintain. It’s like your body’s Ferrari—it needs a lot of energy, and fat contains a lot of energy. Perhaps the most significant evolutionary change in the modern human was growth of the brain, from 850 to 1,200 cubic centimeters as Homo erectus (between 1.5 million and 130,000 years ago) to 1,350 to 1,400 cubic centimeters as Homo sapiens (first showing up 130,000 years ago). Humans expend a much larger share of their resting energy budget on brain metabolism than do other primates or non-primate mammals. Where do we get the energy to support our metabolically expensive brains? From high-energy fat. Research on the diets of primates shows that the high cost of a large human brain is supported by diets that are rich in fat. Greater brain size also appears to have consequences for human body composition, particularly when we are young. Human infants have more body fat than do the infants of other mammals, which enables human brains to grow by having a ready supply of stored energy. Interestingly, when dietary fat is not readily available, human infants and toddlers preserve their body fat by stunting their body’s linear growth and even increase the amount of fat they store, so the brain has enough for itself. From an evolutionary perspective, the increased consumption of fat—and thus the energy that comes with it—appears to have been necessary for promoting brain growth in humans. Fat also helps to produce hormones, is an important component of cell membranes, contributes to nerve function, and carries the fat-soluble vitamins A, D, E, and K into your bloodstream.
Although there are successful weight losers who consume a greater percentage of calories from fat and a lesser percentage from carbohydrate (e.g., individuals who have lost weight with bariatric surgery115), controlling the amount of fat in the diet is the more robust strategy of the NWCR to control total calories and defend against a growing waistline. Research independent of the NWCR has also found that the most successful weight losers reduce the percentage of calories from fat in their diets.116-118 Those who consume cheese, butter, high-fat snacks, fried foods, and desserts less than once per week are more successful at long-term weight control.119
In the early 2000s, the fat content of the NWCR members’ diet increased and the carbohydrate content of their diet decreased compared to earlier years. At that time, low-carb diets were becoming all the rage, with people pushing away the pasta and potatoes in favor of more fat and protein. The decrease in carbohydrate content of the diet seems to have come from a decrease in “bad carbs,” like processed foods with added sugar, since, also during that time, NWCR members increased their consumption of vegetables to nearly four servings per day and increased their consumption of fiber from vegetables, fruit, and beans.120 The opposite habit—an increase in dietary sweets—is a significant predictor of weight regain.121
The percentage of NWCR members consuming a low-carbohydrate diet (less than 90 grams, which is less than 25 percent of daily calories) increased from 5.9 percent in 1995 to 7.6 percent in 2001 to 17.1 percent in 2003, although it still remains low for successful weight losers, despite the media’s attention on low-carbohydrate diets. Even with the increasing percentage of NWCR members consuming a low-carbohydrate diet, the fat content of the diet still remains far below the national average. Hardly anyone in the NWCR is consuming a very low-carbohydrate or ketogenic diet. The word “ketogenic” doesn’t even exist in any of the NWCR’s published studies.
This slight shift in the macronutrient composition of the NWCR members’ diet came with consequences. When weight fluctuations were examined after one year, in light of the change in macronutrient composition, the increased percentage of calories from fat and decreased percentage of calories from carbohydrate were significantly related to weight regain. In other words, the lower-carb approach isn’t working in the long term. This is a robust finding of the NWCR: weight regainers decrease their carb intake and increase their fat intake, whereas maintainers keep their fat intake consistently low. NWCR members who consume less than 24 percent of their daily calories from carbohydrate maintain their weight loss for less time and are less physically active than members who consume a high-carbohydrate diet.122
While interesting, it’s little surprise that low-carbohydrate dieters exercise less than high-carbohydrate dieters. With a low-carbohydrate diet, it becomes very difficult to exercise a lot since carbohydrate is the muscles’ preferred exercise fuel. Since the members of the NWCR are not asked why they consume a high-carbohydrate diet, it can only be speculated, but is likely due to the fact that they exercise a lot. Carbohydrate is vital for exercise. Muscle biopsy research since the 1960s has shown that exercise requiring cardiovascular endurance is strongly influenced by the amount of carbohydrate stored in skeletal muscles (called glycogen), with muscle glycogen depletion becoming the decisive factor limiting prolonged moderate- to high-intensity exercise. That muscles prefer carbohydrate as a fuel is fundamental to exercise metabolism, even research examining supplementation with carbohydrate during exercise has shown that fatigue can be delayed.123
To find out why muscles prefer carbohydrate, we have to go all the way back to the time life on Earth began. A long time ago, before you and I were born, the atmosphere of primitive Earth was thought to have been made up of hydrogen and contained little or no oxygen. So, the earliest organisms on Earth had to develop an anaerobic (non-oxygen-using) way of producing energy. Since carbohydrate can be broken down without oxygen—which distinguishes it from fat, which can be broken down only in the presence of oxygen—organisms relied on carbohydrate. Millions of years later, carbohydrate is still your muscles’ fuel of choice.
When your carbohydrate fuel tank is low, your body doesn’t perform well, and exercise, especially of a high intensity, becomes laborious. Brain function is also impaired by a lack of carbohydrate. If you don’t have enough carbs, you literally can’t think straight, and your reasoning skills diminish. In order to exercise at a high intensity, prevent hypoglycemia (low blood sugar), refuel your muscles, and strengthen your immune system, you need to eat enough carbs. Your body’s store of carbohydrate (as glycogen in your muscles and liver) is relatively limited and can be acutely manipulated on a daily basis by your dietary intake or even by a single workout.
One NWCR study compared low-carbohydrate weight losers (e.g., those who used Atkins diet, South Beach diet, or another low-carb diet) to all other NWCR members who enrolled in the registry between 1998 and 2001 (the time when the Atkins diet and other low-carbohydrate diets were becoming popular).124 Only 10.8 percent said they lost weight with a low-carbohydrate diet. At the time they entered the NWCR, the low-carb weight losers lost less weight than the non-low-carb weight losers (60.7 pounds vs. 70.6 pounds, respectively) and had kept their weight off for less time than the non-low-carb weight losers. Their diet was 9.5 percent carbohydrate and 64.0 percent fat (compared to 48.2 percent carbohydrate and 30.9 percent fat for the non-low-carb weight losers). Three years later, their diet had changed to 16.9 percent carbohydrate and 58.8 percent fat (the non-low-carb weight losers’ diets had not changed). As had been shown in earlier research, the low-carb weight losers were much less physically active than the non-low-carb weight losers (burning 1,595 calories per week at registry entry, and 1,119 calories per week three years later vs. burning 2,542 calories per week at entry, and 2,246 calories per week three years later, respectively), however, they did not gain significantly more weight over the three years compared to the non-low-carb weight losers. (Low-carb weight losers gained 8.4 pounds after one year, 9.9 pounds after two years, and 14.3 pounds after three years; non-low-carb weight losers gained 5.1 pounds after one year, 8.8 pounds after two years, and 10.3 pounds after three years.) Other research independent of the NWCR on a random sample of weight losers has shown that low-carb dieters experience greater weight regain compared to non-low-carb dieters six to twelve months after starting their diet.125 Since the low-carb dieters of the NWCR were already successful weight losers when they entered the registry, it is possible, albeit not the norm, to be a successful weight loser on a low-carb diet in the presence of other self-regulating behaviors.
Since there are three macronutrients, we can’t forget about protein amid all this talk of fat and carbohydrate. Like an army of construction workers amid a building’s scaffolding, protein is used for construction inside your body. The protein you eat is broken down into amino acids, the metaphorical bricks that are used to repair and maintain muscle mass, build new functional proteins and cells in response to specific stimuli, like exercise (e.g., mitochondria, enzymes, red blood cells, and antibodies), and build transport proteins that move molecules from one place to another (e.g., albumin, which transports fatty acids to your muscles and liver for oxidation when your blood sugar is low). Protein also makes you feel fuller, and helps control appetite. If you lack protein in your diet, not only are you likely to feel hungry more often, you’re more likely to experience a decrease in muscle mass, suppressed immune system, increased risk of injury, and chronic fatigue. People at risk of insufficient protein intake include those on a very low-calorie or vegetarian or vegan diet. (Low-calorie diets put all nutrients at risk for being insufficient, and plant proteins are less well digested than animal proteins.) Diets that contain 0.4 gram per pound of body weight per day are effective for weight and fat loss when reducing calories to lose weight, while higher-protein diets that contain 0.5 to 0.7 gram per pound of body weight per day, and include at least 25 to 30 grams of protein per meal, provide improvements in appetite, body-weight management, and reduction in risk factors for cardiovascular and metabolic diseases.
Although the emphasis of so-called “low-carb” diets is on carbohydrate, it is primarily the relatively high-protein content of the diet that is responsible for the success that people have with such diets. That was the conclusion of scientists at the Nutrition and Toxicology Research Institute in the Netherlands, when they compared body weight and percent body fat (as well as many other variables) of 132 individuals who were randomly assigned one of four diets for twelve months: (1) low carbohydrate/high protein, (2) low carbohydrate/normal protein, (3) normal carbohydrate/high protein, and (4) normal carbohydrate/normal protein.126 By manipulating the carbohydrate and protein contents of the diets, the scientists sought to find out whether it is the lower carbohydrate or the higher protein content of the diet that influences weight loss and maintenance. After the subjects consumed the diet for two weeks, the total calories of the four diets were reduced to 33 percent for the next three months to induce weight loss. For the next nine months after that, total calories were increased to 67 percent that of the first two weeks to maintain weight. After both the three-month weight-loss phase and the nine-month weight-maintenance phase, the amount of physical activity the subjects did had not changed, nor did it differ between groups. Here’s what the macronutrient composition of the four diets looked like, with the subjects’ body weight and percent body fat at the end of each phase:
|
Low Carb High |
Low Carb Normal Protein |
Normal Carb High |
Normal Carb Normal Protein |
|
|
Phase 1 (2 weeks) % Carb/Protein/Fat |
25/20/55 |
25/10/65 |
50/20/30 |
50/10/40 |
|
Phase 2 (3 months) % Carb/Protein/Fat |
5/60/35 |
5/30/65 |
35/60/5 |
35/30/35 |
|
Phase 3 (9 months) % Carb/Protein/Fat |
25/30/45 |
25/15/60 |
45/30/25 |
45/15/40 |
|
Phase 1 (2 weeks) Body Weight (lbs.) % Body Fat |
238 41.5 |
236 45.4 |
233 45.9 |
232 45.2 |
|
Phase 2 (3 months) Body Weight (lbs.) % Body Fat |
206 35.3 |
209 40.7 |
203 39.9 |
208 41.2 |
|
Phase 3 (9 months) Body Weight (lbs.) % Body Fat |
212 36.6 |
215 41.7 |
207 40.7 |
214 42.1 |
As you can see in the table, body weight and percent body fat decreased during the three-month weight-loss phase with all four diets. When calories were increased over the next nine months during the weight maintenance phase, the subjects regained some weight. There was a significant difference in the amount of weight loss between the high-protein and normal protein diets (average of 31 pounds vs. 25.5 pounds), but not between the low-carb and normal-carb diets (average of 29.5 pounds vs. 27 pounds). This was also the case after twelve months. Weight loss and weight maintenance depend on the high-protein, not on the low-carb, component of the diet. The fat content of the diets also had no effect on weight loss or weight maintenance. The scientists suggest that increasing the protein content of the diet while reducing calories may cause a greater feeling of fullness (i.e., satiety), which assists weight loss and maintenance. Research from the NWCR has shown that people who consume less protein are more likely to regain weight, compared to those who consume more protein.127
Manipulating macronutrients seems to be a fun exercise for scientists, as well as for the general public of dieters. What would happen to total calories of the diet if one macronutrient were increased by 1 percent while another macronutrient was decreased by 1 percent? That was the question posed by researchers at the University of Illinois, Urbana-Champaign.128 Using data from years of calorie and macronutrient compositions of diets from the National Health and Nutrition Examination Survey (NHANES), a well-known research program conducted by the National Center for Health Statistics to assess the health and nutritional status of adults and children in the United States, the researchers found that substituting protein or carbohydrate for fat and substituting protein for carbohydrate all cause daily calories to decrease, with the largest effect coming from substituting protein for fat. Specifically, increasing the percentage of calories from protein by just 1 percent while decreasing the percentage of calories from fat by just 1 percent—a 1 percent protein-for-fat exchange—caused total daily calories to decrease by 64, 69, and 70 calories for normal-weight, overweight, and obese men, and 42, 45, and 49 calories for normal-weight, overweight, and obese women, respectively. When it comes to reducing calories, protein is kind of special: exchanging it for fat (and, to a lesser degree, for carbohydrate) makes a big difference.
One way to ensure your macronutrients are balanced to provide optimal energy for life’s daily activities and to support your weight-loss success is to be consistent with your diet. The members of the NWCR who maintain the same diet across the week and throughout the year are more likely to maintain their weight loss over the following year than members who diet more strictly only on weekdays and/or during non-holiday periods.129 Although variety has been called the spice of life, it’s not the spice of successful weight losers. They limit variety in their diets, avoiding the weekend and holiday splurges and treats, probably because it’s more difficult to control calories and macronutrient percentages when eating a large variety of foods each week. If you eat the same thing (or similar things) every week, it’s much easier to maintain specific percentages of fat, carbs, and protein than if you’re eating completely different meals every week. One study that compared diet variety between 2,237 NWCR members and recent weight losers who had not yet become successful weight losers found that the NWCR members consumed less variety from low-fat-dense food groups than the recent weight losers.130 The largest difference in food group variety between the NWCR members and the recent weight losers was found in the food group from the top of the Food Guide Pyramid: fats, oils, and sweets, with NWCR members having less variety than recent weight losers. Although overall dietary variety is low in NWCR members, they consume more variety in nutrient-dense and low-fat-dense foods (i.e., the bottom of the Food Guide Pyramid) than in other food groups. In other words, successful weight losers are not wasting calories on foods and beverages that don’t provide nutrition (e.g., fast-food restaurants, Starbucks, desserts, etc.). The researchers found that the variety consumed among all food groups was positively correlated to caloric intake—the more variety, the more calories consumed.
To model your diet after the NWCR, consume about 55 percent carbohydrate, 25 percent fat, and 20 percent protein. These percentages don’t have to be exact; you ultimately need to find the macronutrient composition that works for you for the rest of your life. To support your level of physical activity, eat less carbohydrate at times when you are less physically active, and eat more carbohydrate at times when you are more physically active. If you reduce the percentage of carbohydrate, make up the difference with protein rather than with fat. Remember that with every gram of fat you eat or drink, you’re consuming more than twice the number of calories you consume with carbohydrate and protein. Eating a low-fat, high-carbohydrate diet doesn’t mean eating a huge plate of pasta at every dinner or eating lots of chocolate chip cookies. It means eating healthy carbohydrate, like fruits, vegetables, and whole grains. That’s the habit of the successful weight losers.
Creating the Habit
There are several ways to create the habit of eating a low-fat, high-carbohydrate diet:
1) Plan your meals each week. Be diligent about this, otherwise the specifics of what you eat can get out of hand. Planning can prevent that from happening.
2) Every time you go to the supermarket, fill up your shopping cart with greens, fruits, and vegetables before putting anything else in your cart. Create in your mind the association of “supermarket” with “greens, fruits, and vegetables.” For supermarket items that are typically high in fat, choose the low-fat options. Read the nutrition labels. If it’s too difficult to place kale in your shopping cart instead of potato chips, have someone else go grocery shopping for you. If you don’t have processed carbs and fatty foods in your shopping cart, they won’t be in your home. If processed carbs and fatty foods are not in your home, you can’t eat them. Out of sight, out of mind will work after a while.
3) Create cues in your home to eat more healthy carbohydrate and less fat. Keep a fruit bowl on the dining room table or island in your kitchen. Set a morning fruit alarm to eat fruit before you eat anything else.
4) Consult a registered dietitian or qualified nutritionist to create a meal plan for you. Following a professional’s advice can eliminate the guesswork of you having to figure it out on your own.
5) Include a high-protein food at each meal. Add an egg to your breakfast oatmeal, turkey or tuna to your lunch salad, and salmon to your dinner.
6) Keep a food journal. For a few weeks to a few months, write down what you eat at every meal. Although it may seem like a pain to write everything in a journal, it will make you aware of what you currently eat and will show you where to make changes. For example, after reviewing what you wrote, you may discover that your diet has been higher in fat or lower in protein than what is optimal, and you’ll be alerted to make a change in one or more macronutrients. After a while, you’ll no longer need to write down what you eat, as consuming the specific foods that will help you achieve your goals becomes a habit.
Remember, for a behavior to become a habit, it must become automatic. If you repeatedly practice these strategies, the behaviors will eventually become automatic.
***
After her first Weight Watchers meeting in 2008 at age fifty, Diann Marten realized she had found a place where she could get help and be inspired. “I sat in my car after the meeting and sobbed uncontrollably with relief, because I knew that I had found what I needed,” she says. In addition to Weight Watchers, she listened to a podcast called Inside Out Weight Loss, which helped her work through her food issues. By 2011, Diann had lost 72 pounds to reach her goal weight of 181 pounds. At one of the Weight Watchers’ meetings, she heard about the NWCR and decided to join. “My weight had been such an issue for so long, and I wanted to help others understand that if I can lose and maintain it, they can, too.”
In 2016, her weight crept back up to around 210, which she again lost, and has hovered around 193 pounds ever since. She has kept off sixty pounds for nine years. “I’m still working on mindful eating,” she says. “At times I overeat, because I’m stressed or bored or because the food is there, but I don’t remember the last time I binged.”
Diann’s knee pain and plantar fasciitis are gone. She plays tennis four hours per week and takes an intense yoga class at least once per week, which keeps her strong so she can keep up with her grandsons.
“There were hard times with weight loss, times when I plateaued or didn’t feel like tracking my food,” she says. “Those were the times when I needed my Weight Watchers group or the podcast the most. There were also really easy times when everything was working beautifully. Now, most of the time, it’s pretty easy. It’s still hard when I’m stressed or when I get down on myself. I learned that it’s important to slow down and enjoy my food. I try to find joy in each day, and part of that joy is eating wonderful, healthy foods. I learned that I can eat! I had so much guilt around food before I found a podcast that helped me work through my food issues.”
When Diann’s weight increases, she logs her food to kickstart a loss. Nighttime eating is sometimes still an issue. “I’m trying to develop the habit of having a small dinner and either nothing or a small, healthy snack before bed,” she says. She eats lots of fruits and vegetables and makes those her go-to foods if she feels a need to munch when she’s not really hungry. She pays attention to her food and makes her meals attractive. She often uses a smaller plate or bowl. “I try to look for opportunities, not obstacles, so if I’m at a buffet, I search out great-looking fruits or veggies and good, lean proteins,” she says. “I indulge and I’m determined not to feel guilty about it.”
When asked what advice she has for others who want to become successful weight losers, Diann says, “You need to tell yourself how great you are, and never talk badly to yourself. If you fail, you’re learning. Any diet can work, but you must focus on living it. It’s easy to stay on a diet for a week, but for long-term change, pick a plan that you can live with and one that will help you change your habits for good. And find the support of a trusted friend or group.”
What about that twelve-day trip to France during which Diann indulged on daily dessert with her friend? “I came home weighing exactly the same as when I left, even with a glass or two of wine every day!” she says.
Habit 4
Eat A Low-Fat, High-Carbohydrate Diet.