Fitting in Exercise

 

Exercise is one tool you have to control your weight because exercise is a way to increase the number of calories that you burn in a day. Online resources like this exercise calculator show you how many calories different forms of exercise can burn. One way to make the most of exercise is to integrate some form of exercise into your daily routine. Here are several examples:

• Try to find some type of exercise that you enjoy (or at least can tolerate) and do it every day for 30 minutes, 60 minutes or more. It might be walking, riding an exercise bike while watching TV, or working out in a gym at lunch.
• Try to fit micro-exercises into your daily life. For example, instead of taking the elevator, take the stairs. Park farther away from stores when you go shopping. These little things can add up.
• Put a set of weights at your desk and use them three or four times during the day, as you think or talk on the phone.
• Find an exercise partner. Exercise, for some people, is a lot easier if there is someone to talk to. A partner will also help make exercise a routine.
• Try to exercise every day. It is easier to remember to do something if you do it every day.

Building a Sustainable Diet

 

Photo courtesy USDA
The new USDA Food Pyramid.

Building a sustainable diet and exercise plan is the key to maintaining a consistent weight. This is not easy for many people. As described in the previous sections, the landscape is literally covered with calories, and exercise takes time and energy.

The first step to building a sustainable diet is to start counting the calories that you consume in a day so that you become conscious of two things:

• You need to understand exactly how many calories you are eating on a "normal" day.
• You need to realize where each calorie comes from -- you need to build a calorie database in your brain so that you know, whenever you eat something, just how many calories it is supplying.

In the United States, any food that you buy in the grocery store is required by the U.S. Food & Drug Administration to have a nutritional label with that food's calorie content. You can also look at a chart like this one to find out the number of calories in different foods. Any chain restaurant will supply you with nutrition information both at the store and on the Web (or you can see a Web site like this).

The second step is to figure out how many calories you need in a day. You can use the "12 calories per pound" rule, or you can get more precise by looking at the formulas in How Calories Work.

Pick your "ideal weight" -- the weight that you would like to maintain. Then calculate how many calories a day you can consume to maintain that weight.

The third step is to compare the two numbers -- You may be startled by the difference between the "number of calories you need" and "the number of calories that you take in" in a day. That is where the extra pounds are coming from.

The fourth step is to figure out how to bring the two numbers in line. What you will soon realize is that 1,600 or 1,800 or 2,000 calories per day just isn't that many. You have to watch and count everything you eat and drink every day and stick to your daily limit.

The fifth step might be to add exercise to the mix so that you can raise the number of calories you can consume per day. Online resources like this exercise calculator will show you how many calories different forms of exercise can burn. Burning 250 or 500 calories per day through exercise can make a big difference.

How Dieting Works

Let's imagine that you are overweight and you would like to lose several excess pounds. To lose 1 pound of fat, what you have to do is burn off 3,500 calories. That is, over a period of time, you have to consume 3,500 calories less than your body needs. There are several ways you can create that deficit. If you assume that you weigh 150 pounds and that your body at rest needs 1,800 calories per day (150 * 12 = 1,800) to live, here are several examples (some realistic, some not):

• You could lie in bed and starve yourself. Since you are lying in bed, you are consuming 1,800 calories per day. Since you are starving yourself, you are taking in no calories. That means that, every day, you create a deficit of 1,800 calories and, approximately every two days, you will lose 1 pound of body weight.
• You could consume fewer calories than your body needs. For example, you might choose to consume 1,500 calories per day rather than the required 1,800 by controlling what you eat. That creates a 300-calorie deficit every day. That means that approximately every 12 days, you will lose 1 pound of weight (12 days x 300 calories = 3,600 calories).
• You could consume 1,800 calories per day and then choose to jog 2 miles (3.2 km) every day. The jogging would burn about 200 calories per day, and over the course of 18 days you would burn about 1 pound of body weight (18 days x 200 calories = 3,600 calories).
• You could consume 2,500 calories per day and run 10 miles per day. You will burn 1,800 calories per day at rest and then 1,000 calories per day running, for a total of 2,800 calories. You are consuming 300 calories fewer than you need, so you would lose a pound every 12 days or so (300 calories x 12 days = 3,600 calories).

As you can see from these examples, the only way to lose fat is to consume fewer calories per day than your body needs. For every 3,500 calories that your body takes from its fat reserves, you lose 1 pound (0.45 kg) of body fat. You can create the deficit either by monitoring and restricting your intake of calories, or by exercising, or both.

The idea behind most diets -- everything from Weight Watchers to the grapefruit diet -- is simply to help you somehow lower the number of calories that you consume each day. That's all they do.

Sample Menu

 

Face it, many of us are over-worked, over-booked and totally over-extended. So, convenient food often takes the lead in our daily diets. In a typical day someone might consume something like this:

• You might have two Pop-Tarts® for breakfast,
• then hit Pizza Hut for lunch,
• grab some SnackWell's and a cola for a snack,
• head for McDonald's for dinner
• and top it off with some potato chips while watching TV.

You can see how the number of calories coming in can easily reach 3,000, 4,000 or 5,000 per day without any effort at all. That's the problem.

Your body, it turns out, is extremely efficient at capturing and storing excess calories. Whenever your body finds that it has excess calories on hand, it converts them to fat and saves them for a rainy day. (See How Calories Work and How Fat Cells Work for details). It only takes 3,500 excess calories to create 1 pound of new fat on your body. If you are taking in just 500 extra calories per day, then you are gaining a pound of fat per week (500 calories x 7 days in a week = 3,500 calories/week). Since it is easy to get 500 calories from just one ice cream cone or a few cookies, you can see that weight gain is completely effortless in today's society. Food is just too easy to find

Taking Calories In

The 1,800 calories that a typical person at rest needs per day is just not that many. For example, if you go to your neighborhood McDonald's restaurant and order the Big Xtra meal, you will get a sandwich, a large order of french fries and a large Coke®. This meal contains:

• 710 calories in the sandwich*
• 540 calories in the french fries*
• 310 calories in the drink*

(*See McDonald's USA Nutrition Facts for details.)

A meal at McDonald's can add up to almost a whole day's worth of calories.

In other words, just this one meal provides 1,560 calories you need during a day. If you get an M&M® McFlurry™ with it for dessert, you'll get 630 more calories, so you are already consuming almost 2,200 calories just at this one meal!

Similarly, if you go to Pizza Hut and get a Meat Lover's Pan Pizza®, each slice contains 360 calories.* If you eat three slices and get a large drink to go with it, that's 1,390 calories -- just 410 calories shy of a full day's worth of calories. (*See the Pizza Hut Nutrition Guide for details.)

Similarly, if you eat 12 SnackWell's Crème Sandwich Cookies -- which, if you think about it, really is not that hard to do -- you've taken in 660 calories. That's more than one-third of the daily caloric intake.

These three cookies contain 165 calories.

The point here is not to slam these products or make them look bad. For example, I've got two kids and I go to McDonald's at least once a week. The point is that, in America and most other developed countries, it is incredibly easy to find and consume calories. Let's take a look at what someone might consume in a typical day.

Your Body's Efficiency

 

Have you ever wondered why, for so many people (and especially for anyone older than 30 years old), weight gain seems to be a fact of life? It's because the human body is way too efficient! It just does not take that much energy to maintain the human body at rest; and when exercising, the human body is amazingly frugal when it comes to turning food into motion.

At rest (for example, while sitting and watching television), the human body burns only about 12 calories per pound of body weight per day (26 calories per kilogram). That means that if you weigh 150 pounds (68 kg), your body uses only about:

150 X 12 = 1,800 calories per day

Twelve calories per pound per day is a rough estimate -- see How Calories Work for details.

Those 1,800 calories are used to do everything you need to stay alive:

• They keep your heart beating and lungs breathing.
• They keep your internal organs operating properly.
• They keep your brain running.
• They keep your body warm.

In motion, the human body also uses energy very efficiently. For example, a person running a marathon (26 miles or 42 km) burns only about 2,600 calories. In other words, you burn only about 100 calories per mile (about 62 calories per km) when you are running.

You can see just how efficient the human body is if you compare your body to a car. A typical car in the United States gets between 15 and 30 miles per gallon of gasoline (6 to 12 km/L). A gallon of gas contains about 31,000 calories. That means that if a human being could drink gasoline instead of eating hamburgers to take in calories, a human being could run 26 miles on about one-twelfth of a gallon of gas (0.3 L). In other words, a human being gets more than 300 miles per gallon (120 km/L)! If you put a human being on a bicycle to increase the efficiency, a human being can get well over 1,000 miles per gallon (more than 500 km/L)!

That level of efficiency is the main reason why it is so easy to gain weight, as we will see in the next section.

Introduction to How Dieting Works

Dieting is one of those things that is completely integrated into American culture. On any given day, a huge portion of the U.S. population is "on a diet" and "counting calories" in one way or another. And look at how many of the diet names in the following list you recognize:

• The Atkins Diet
• The Cabbage Soup Diet
• The Grapefruit Diet
• The Hollywood Miracle Diet
• The Rice Diet
• The Scarsdale Diet
• The South Beach Diet
• The Zone Diet

You probably recognize many of these names because you hear them all the time!

In this article, we will look first at weight gain and why gaining weight is so easy. Then we will look at what you can do about weight gain -- in the form of diet and exercise -- to maintain a consistent weight.

Body weight

Although some people prefer the less-ambiguous term body mass, the term body weight is overwhelmingly used in daily English speech as well as in the contexts of biological and medical sciences to describe the mass of an organism's body. Body weight is measured in kilograms throughout the world, although in some countries people more often measure and describe body weight in pounds (e.g. United States and sometimes Canada) or stones and pounds (e.g. among people in the United Kingdom) and thus may not be well acquainted with measurement in kilograms. Most hospitals, even in the United States, now use kilograms for calculations, but use kilograms and pounds together for other purposes. (1 kg is approximately 2.2 lb; 1 stone (14 lb) is approximately 6.4 kg.)

The term is usually encountered in connection with:

• food and feeding behaviour
• normal and abnormal growth and development
• the physiological and hormonal control of ingestion and digestion
• foraging for food in animals
• hunger and other motivations to eat
• problems in regulating body weight, often resulting in obesity
• eating disorders such as anorexia nervosa and bulimia nervosa
• effects of disease
• athletic competitions where the participants are classified according to their body weight

Food Balance Wheel

The Food Balance Wheel suggests an alternate interpretation of the USDA Food Guide Pyramid^[1] recommendations for balanced eating. Created by author Art Dragon^[2], it converts the principles of the food pyramid from a number-based format to a visual presentation that may be more accessible to users interested in balanced eating.

Low glycemic index

"The glycemic index (GI) factor is a ranking of foods based on their overall effect on blood sugar levels. The diet based around this research is called the Low GI diet. Low glycemic index foods, such as lentils, provide a slower, more consistent source of glucose to the bloodstream, thereby stimulating less insulin release than high glycemic index foods, such as white bread."^[27][28]

The glycemic load is "the mathematical product of the glycemic index and the carbohydrate amount".^[29]

In a randomized controlled trial that compared four diets that varied in carbohydrate amount and glycemic index found complicated results^[30]:

• Diet 1 and 2 were high carbohydrate (55% of total energy intake)
  • Diet 1 was high-glycemic index
  • Diet 2 was low-glycemic index
• Diet 3 and 4 were high protein (25% of total energy intake)
  • Diet 3 was high-glycemic index
  • Diet 4 was low-glycemic index

Diets 2 and 3 lost the most weight and fat mass; however, low density lipoprotein fell in Diet 2 and rose in Diet 3. Thus the authors concluded that the high-carbohydrate, low-glycemic index diet was the most favorable.

A meta-analysis by the Cochrane Collaboration concluded that low glycemic index or low glycemic load diets led to more weight loss and better lipid profiles. However, the Cochrane Collaboration grouped low glycemic index and low glycemic load diets together and did not try to separate the effects of the load versus the index

Low carbohydrate versus low fat

Many studies have focused on diets that reduce calories via a low-carbohydrate (Atkins diet, Scarsdale diet, Zone diet) diet versus a low-fat diet (LEARN diet, Ornish diet). The Nurses' Health Study, an observational cohort study, found that low carbohydrate diets based on vegetable sources of fat and protein are associated with less coronary heart disease.^[12]

A meta-analysis of randomized controlled trials by the international Cochrane Collaboration in 2002 concluded^[13] that fat-restricted diets are no better than calorie restricted diets in achieving long term weight loss in overweight or obese people. A more recent meta-analysis that included randomized controlled trials published after the Cochrane review^[14][15][16] found that "low-carbohydrate, non-energy-restricted diets appear to be at least as effective as low-fat, energy-restricted diets in inducing weight loss for up to 1 year. However, potential favorable changes in triglyceride and high-density lipoprotein cholesterol values should be weighed against potential unfavorable changes in low-density lipoprotein cholesterol values when low-carbohydrate diets to induce weight loss are considered."^[17]

The Women's Health Initiative Randomized Controlled Dietary Modification Trial^[18] found that a diet of total fat to 20% of energy and increasing consumption of vegetables and fruit to at least 5 servings daily and grains to at least 6 servings daily resulted in:

• no reduction in cardiovascular disease^[19]
• an insignificant reduction in invasive breast cancer^[20]
• no reductions in colorectal cancer^[21]

Additional recent randomized controlled trials have found that:

• A comparison of Atkins, Zone diet, Ornish diet, and LEARN diet in premenopausal women found the greatest benefit from the Atkins diet.^[22]

• The choice of diet for a specific person may be influenced by measuring the individual's insulin secretion:

In young adults "Reducing glycemic [carbohydrate] load may be especially important to achieve weight loss among individuals with high insulin secretion."^[23] This is consistent with prior studies of diabetic patients in which low carbohydrate diets were more beneficial.^[24][25]

The American Diabetes Association released for the first time a recommendation (in its January 2008 Clinical Practice Recommendations) for a low carbohydrate diet to reduce weight for those with or at risk of Type 2 diabetes.

Side effects

Side effects

Dieting, especially extreme food-intake reduction and rapid weight loss, can have the following side effects:

• Prolonged hunger
• Depression
• Reduced sex drive
• Fatigue
• Irritability
• Fainting
• Sinus problems (especially post-nasal drip)
• Muscle atrophy
• Rashes
• Acidosis
• Bloodshot eyes
• Gallbladder disease
• Seizures
• Malnutrition, possibly leading to death
• Subsequent weight gain

Weight loss groups:Dangers of fasting

Lengthy fasting can be dangerous due to the risk of malnutrition and should be carried out under medical supervision. During prolonged fasting or very low calorie diets the reduction of blood glucose, the preferred energy source of the brain, causes the body to deplete its glycogen stores. Once glycogen is depleted the body begins to fuel the brain using ketones, while also metabolize body protein (including but not limited to skeletal muscle) to be used to synthesize sugars for use as energy by the rest of the body. Most experts believe that a prolonged fast can lead to muscle wasting although some dispute this. The use of short-term fasting, or various forms of intermittent fasting have been used as a form of dieting to circumvent this issue.

Weight loss groups: Stimulants

Stimulants such as ephedrine, green tea, caffeine or synephrine work to increase the basal metabolic rate.^[

Weight loss groups:Diuretics

Diuretics

Diuretics induce weight loss through the excretion of water. These medications or herbs will reduce overall body weight, but will have no effect on an individual's body fat. Diuretics can thicken the blood, cause cramping, kidney and liver damage. In a single report, the death of Jacqueline Henson was found to be related to swelling in her brain, which was associated with excessive water consumption over a short period of time, while she was on a special water diet

Weight loss groups:Medications

Certain medications can be prescribed to assist in weight loss. The most recent prescription weight loss medication released is Acomplia (generic name Rimonabant), manufactured by Sanofi Aventis. Used to treat obesity in persons with a BMI ( body mass index) of 30 or above as well as for smoking cessation treatments, Acomplia is still pending FDA approval for use in the United States. Other weight loss medications, like amphetamines, are dangerous and are now banned for casual weight loss. Some supplements, including those containing vitamins and minerals, may not be effective for losing weight.

Food diary

Food diary

A July 2008 study, published in the American Journal of Preventive Medicine, showed dieters who keep a daily food diary (or diet journal) of what they eat lose twice as much weight as those who do not. The researchers concluded, "It seems that the simple act of writing down what you eat encourages people to consume fewer calories."^[10] Diet journaling software and websites have become popular to help people track calorie consumption, calorie burning, weight loss goals, and nutritional balance.

Weight loss groups

There exist both profit-oriented and non-profit weight loss organizations who assist people in their weight loss efforts. An example of the former is Weight Watchers; examples of the latter include Overeaters Anonymous, as well as a multitude of non-branded support groups run by local churches, hospitals, and like-minded individuals.

These organizations' customs and practices differ widely. Some groups are modelled on twelve-step programs, while others are quite informal. Some groups advocate certain prepared foods or special menus, while others train dieters to make healthy choices from restaurant menus and while grocery-shopping and cooking.

Most groups leverage the power of group meetings to provide counseling, emotional support, problem-solving, and useful information

Psychological aspects of weight-loss dieting

Diets affect the "energy in" component of the energy balance by limiting or altering the distribution of foods. Techniques that affect the appetite can limit energy intake by affecting the desire to overeat.

Cognitive Behavior Therapy has been effective in producing long term weight loss ^[8]. Judith S. Beck has been one of the most prominent practitioners and writers to bring this method to a popular audience.

Consumption of low-energy, fiber-rich foods, such as non-starchy vegetables, is effective in obtaining satiation (the feeling of "fullness"). Exercise is also useful in controlling appetite as is drinking water and sleeping.

The use of drugs to control appetite is also common. Stimulants are often taken as a means to suppress hunger in people who are dieting. Ephedrine (through facilitating the release of adrenaline and noradrenaline) stimulates the alpha(1)-adrenoreceptor subtype, which is known to act as an anorectic. L-Phenylalanine, an amino acid found in whey protein powders also has the ability to suppress appetite by increasing the hormone cholecystokinin (CCK) which sends a satiety signal to the brain.

How the body gets rid of fat

How the body gets rid of fat

All body processes require energy to run properly. When the body is expending more energy than it is taking in (e.g. when exercising), the body's cells rely on internally stored energy sources, like complex carbohydrates and fats, for energy. The first source the body turns to is glycogen (by glycogenolysis). Glycogen is a complex carbohydrate, where 65% of it is stored in skeletal muscles and the rest in the liver (totaling about 2000 kcal in the whole body). It is created from the excess of ingested macronutrients, mainly carbohydrates. When those sources are nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process, fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to make energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.

Proper nutrition

Food provides nutrients from six broad classes: proteins, fats, carbohydrates, vitamins, dietary minerals, and water. Carbohydrates are metabolized to provide energy. Proteins provide amino acids, which are required for cell construction, especially for the construction of muscle cells. Essential fatty acids are required for brain and cell membrane construction. Vitamins and trace minerals help maintain proper electrolyte balance and are required for many metabolic processes. Dietary fiber is another food component which influences health even though it is not actually absorbed into the body.

Any diet that fails to meet minimum nutritional requirements can threaten general health (and physical fitness in particular). If a person is not well enough to be active, weight loss and good quality of life will be unlikely.

The National Academy of Sciences and the World Health Organization publish guidelines for dietary intakes of all known essential nutrients.

Sometimes dieters will ingest excessive amounts of vitamin and mineral supplements. While this is usually harmless, some nutrients are dangerous. Men (and women who don't menstruate) need to be wary of iron poisoning. Retinol (oil-soluble vitamin A) is toxic in large doses. As a general rule, most people can get the nutrition they need from foods. In any event, a multivitamin taken once a day will suffice for the majority of the population.

Weight-loss diets which manipulate the proportion of macronutrients (low-fat, low-carbohydrate, etc.) have not been found to be more effective than diets which maintain a typical mix of foods with smaller portions and perhaps some substitutions (e.g. low-fat milk, or less salad dressing).^[7] Extreme diets may, in some cases, lead to malnutrition.