How to lose weight

 | September 1, 2006

How to lose weight

Eat less, exercise more. If only it were that simple! As most dieters know, losing weight can be very challenging. As we've seen, a range of influences can affect how people gain and lose weight. But a basic understanding of how to tip your energy balance in favor of weight loss (see Figure 5) is a good place to start.

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Counting calories: Doing the math

Start by determining how many calories you should consume each day. To do so, you need to know how many calories you need to maintain your current weight. Doing this requires a few simple calculations.

First, multiply your current weight by 15 — that's roughly the number of calories per pound of body weight needed to maintain your current weight if you are moderately active. Moderately active means getting at least 30 minutes of physical activity a day in the form of exercise (walking at a brisk pace, climbing stairs, or active gardening). Let's say you're a woman who is 5 feet, 2 inches tall and weighs 150 pounds, and you need to lose about 12 pounds to put you in a healthy weight range. If you multiply 150 by 15, you will get 2,250, which is the number of calories per day that you need in order to maintain your current weight (weight-maintenance calories). To lose weight, you will need to get below that total.

For example, to lose 1 to 2 pounds a week — a rate that experts consider safe — your food consumption should provide 500–1,000 calories less than your total weight-maintenance calories. If you need 2,250 calories a day to maintain your current weight, reduce your daily calories to 1,250–1,750. If you are sedentary, you will also need to build more activity into your day. In order to lose at least a pound a week, try to do at least 30 minutes of physical activity on most days, and reduce your daily calorie intake by at least 500 calories. However, calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional. Eating too few calories can endanger your health by depriving you of needed nutrients.

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Meeting your calorie target

How can you meet your daily calorie target? One approach — probably the most accurate — is to add up the number of calories per serving of all the foods that you eat, and then plan your menus accordingly. You can buy books that list calories per serving for many foods. In addition, the nutrition labels on all packaged foods and beverages provide calories per serving information. Make a point of reading the labels of the foods and drinks you use, noting the number of calories and the serving sizes. Many recipes published in cookbooks, newspapers, and magazines provide similar information.

If you hate counting calories, a different approach is to restrict how much and how often you eat, and to eat meals that are low in calories. Indeed, dietary guidelines issued by the American Heart Association stress common sense in choosing your foods rather than focusing strictly on numbers, such as total calories or calories from fat. Whichever method you choose, research shows that a regular eating schedule — with meals and snacks planned for certain times each day — makes for the most successful approach. The same applies after you have lost weight and want to keep it off. Sticking with an eating schedule increases your chance of maintaining your new weight.

Some people focus on reducing the fat in their eating plan because, at 9 calories per gram, fat by weight contains more than twice as many calories as carbohydrates or proteins (4 calories per gram). By substituting lean cuts of meat for fatty ones, avoiding high-fat packaged foods and snacks, and refraining from fat-rich products such as butter, mayonnaise, and salad dressings, you can cut out dozens or even hundreds of calories per day. On the other hand, many people mistakenly think that cutting fat always means cutting calories. Some fat-free foods actually contain more calories than the regular versions because manufacturers use extra sugar to make up for the flavor lost in removing the fat. Moreover, low-fat or nonfat foods are not low-calorie if you consume them in large quantities.

Here are some guidelines to follow when straight calorie counting is impractical.

Eat foods that are filling and low in calories. That means meals and snacks made with whole grains, such as brown rice, whole-wheat bread, and oatmeal, as well as legumes, such as lentils and other beans.

When you eat meat, cut out fat and cut down portion sizes. Choose lean cuts of meat and modest amounts — about 3½ or 4 ounces per serving.

Avoid fried foods. Frying foods adds fat and calories. For stovetop cooking, it's better either to stir-fry foods in nonstick pans lightly coated with a cooking-oil spray or to braise them in broth or wine. Baking, broiling, and roasting add no extra fat to your meals.

Use low-fat or nonfat dairy foods. Milk, yogurt, and cheese are good sources of protein and calcium, but the whole-milk versions of these dairy products are very high in fat.

Avoid fast foods. Hamburgers, chicken nuggets, French fries, and other fast-food meals and snacks tend to promote weight gain for two reasons. First, they are high in fat, calories, or both. Second, the "value meals" are often excessively large and tempt you to overeat.

Avoid high-fat and high-carbohydrate snacks. Both types of snacks are high in calories. Even snacks labeled "low-fat" are often high in calories because they contain large amounts of sugars and other carbohydrates.

Watch what you drink. Regular sodas, fruit juices, and, especially, alcoholic beverages are high in calories (see "Calories from drinks").

Eat scheduled meals and snacks. It may seem that skipping meals or cutting out snacks is a smart way to cut out calories, but doing either of these things can work against you. You need to eat regularly, even when you're on a diet. If you don't, you'll feel so hungry that you may give up in frustration.

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Physical activity: How much is enough?

If one person cuts back on calories without exercising and another person increases exercise without cutting back on calories, the first person would lose weight more quickly. That's because it's easier to cut 500 calories a day from your diet than it is to burn 500 extra calories through exercise. You'd have to walk or run about 5 miles a day — or 35 miles a week — to lose 1 pound of fat. But if you only cut back on calories, you're more likely to regain the weight you lose. Why? The body reacts to weight loss as if it were starving and, in response, slows its metabolism. When your metabolism slows, you burn fewer calories — even at rest. When you burn fewer calories, three things can happen. If you continue eating fewer calories, you will either stop losing weight as quickly as you have been, or you'll stop losing weight altogether. If you increase your calorie consumption, you may actually gain weight more quickly than you have in the past. The solution is to increase your physical activity because doing so will counteract the metabolic slowdown caused by reducing calories.

A regular schedule of exercise raises not only your energy expenditure while you are exercising but also your resting energy expenditure — that is, the rate at which you burn calories even when the workout is over and you are resting. Resting energy expenditure remains elevated as long as you exercise at least three days a week on a regular basis. Because it accounts for 60%–75% of your daily energy expenditure, any increase in resting energy expenditure is extremely important to your weight-loss effort. The kinds of vigorous activity that can stimulate your metabolism include walking briskly for 2 miles or riding a bike uphill.

For people who have obesity and who have been sedentary, any amount of physical activity is beneficial, including walking, swimming, and water aerobics. But start out slowly, and gradually increase the pace and duration of such activities. Low-intensity activities — such as taking a short walk or raking leaves — won't raise your resting energy expenditure as much as high-intensity activities will, but they have other advantages. For one thing, they help reduce body fat and build muscles — and muscle tissue burns more calories than fat does. Regular weight lifting also builds muscle and has a similar effect.

Another benefit of regular physical activity of any sort is that it temporarily curbs your appetite. Of course, many people joke that after a workout they feel extremely hungry — and promptly indulge in a snack. But because exercise raises resting energy expenditure, people continue to burn calories at a relatively high rate. So a moderate snack after exercising does not erase the benefits of exercise in helping people control their weight.

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Starting an exercise program

Many people are daunted by the prospect of starting an exercise program, but it doesn't need to be overwhelming. One approach is to look at your schedule and determine where you can regularly fit in a 30-minute exercise session. For some people, this may mean getting up a half-hour earlier. For others, lunchtime or after work is most convenient. Your goal is to improve your health and lose pounds by doing 30 minutes or more of an activity that's moderately intense, five days a week. If you don't reach this goal at first, it's good to know that any increase in physical activity is better than none.

For some people, a less structured approach may work. You don't have to work out at the gym or participate in a sport, although some people find that these things help them stick to a routine. Many ordinary everyday activities count as moderate-intensity exercise: taking the stairs instead of the elevator, walking instead of driving, cutting the lawn with a push mower, or playing with the children. A significant plus for busy people is that the physical activity doesn't have to be done in a single session. You can break up the 30 minutes — for example, by taking a 10-minute walk to the post office and later having a 20-minute bike ride with the kids. Research has shown that breaking up physical activity into 10-minute spurts throughout the day burns up at least as many calories as exercising in a single block of time. Once people get into the habit of setting aside time on most days for physical activity, they tend to be more open to new kinds of activities — because they feel stronger and more capable of exerting themselves. People who had never considered taking up a new sport might find themselves wielding tennis racquets, strapping on cross-country skis, or joining a recreational volleyball team. Becoming more active over time helps the effort to keep pounds off.

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Behavior modification: Adopting healthier habits

Calorie restriction and exercise help many people lose weight, but only for as long as they keep up the effort. And the same environmental and psychological factors that accounted for the weight gain in the first place can play a role in causing someone to stop exercising or start consuming too many calories. The difficulty in sustaining a diet and exercise routine is one of the main reasons that people who lose weight fail to keep it off. But the difference between long-term success and failure is the ability to make the changes in your diet and activity level permanent.

Certain strategies are useful for everyone who wants to lose weight, regardless of the main causes or severity of their obesity. Many of the following strategies seem like common sense, but they are easily overlooked. You're most likely to follow them if you plan for them in advance.

Eat slowly. Chewing and swallowing your food at a leisurely pace can help you keep from overeating. Here's why: It takes about 20 minutes for your brain to "tell" you when you feel full. Until then, you continue to feel hungry and want to eat. If you eat quickly, you'll end up consuming more than you need to feel full. But eating slowly gives your brain the time it needs to signal that you've had enough.

Make changes gradually. Don't expect to change your diet and activity level overnight. Instead of switching all at once to a low-calorie eating plan, try gradually decreasing the calories of your meals and snacks. For example, start by cutting out snacking or limiting yourself to certain snacks at certain times of day (such as a mid-morning banana or a late-afternoon apple). Also, gradually reduce the calorie content of particular foods. For example, if you're used to drinking whole milk, first switch to milk with 2% fat; then, as you get used to the taste of less fat, go on to milk with 1% fat and finally to skim milk. Another strategy is to lower the calorie content of one meal at a time. In the first week, you might want to eat a low-calorie breakfast, but keep lunch and dinner the same as before. During the second week, you might reduce the calorie content of your lunch. Finally, you can begin eating low-calorie dinners.

Keep a record. Keeping a daily log of what you eat and what physical activities you engage in can help keep you motivated to stay with your diet and exercise plan. Looking over a week's worth of entries can tell you how successful you've been and can help you identify areas where you need to improve.

Seek social support. You'll find it easier to maintain behavioral changes if you have the support and encouragement of others. Social support can come in many forms and from various people. For starters, ask your family members to keep high-calorie foods out of the house, or at least to refrain from eating them in front of you. You might even try to enlist your family to eat the same meals you do. Exercise with someone else, or join a support group. The camaraderie can help keep your spirits up during the inevitable periods when you become discouraged with your progress.

Use a list when buying food. Stick to your grocery list, and steer clear of those aisles or areas with the kinds of calorie-dense foods that you need to avoid.

Out of sight, out of mind. At home, put the most tempting foods high up in the cupboard, at the very back of the fridge, or in other inconvenient spots. Replace the cookie jar and candy bowl with a fruit bowl. Never eat directly out of a large package; many small containers are better than a few large ones, because they provide convenient stopping points. And don't put out too many different varieties of the same kind of food — you'll be tempted to sample from each one and eat a lot more than if you were faced with fewer choices.

Don't go all out when eating out. Eat a low-calorie snack before going out; you're less likely to go off your diet if you're feeling full when you get to the party or restaurant. Go elsewhere for after-dinner coffee so you are less tempted to segue right into dessert.

Make a plan for special occasions. Decide how much you're going to eat before an event, and do your best to stick with that plan. Set some limits before you go to the movies or watch the Sunday afternoon football games. It's so easy to mindlessly munch when you're in front of a screen of any kind.

Be a copycat. When eating with a group of people, look around. Who's eating the least? Who has the healthiest food on their plate? Model your eating habits on those people's.

Find physical activities that you enjoy. For example, if you don't like exercising outdoors on cold days, join a fitness club, or get an exercise bicycle and hand weights to use at home. If the problem is a time crunch, exercise in increments of 10 minutes whenever you have the time — before work, after work, or during your lunch hour.

Reduce stress. If you overeat when you are under stress, find a stress-reduction method that works for you: meditation, relaxation techniques, listening to music, exercising, or talking to a friend.

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Review Date: 2006-09-01

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