Questions and Answers
Our Experts would like to help you with your concerns, regardless of what they are. We have a diverse professional team with expertise in nutrition as well as many other health and lifestyle areas. We will pick as many from your questions as we can and publish them along with their answers on a weekly basis.
What are calories?
Calories are the amount of energy that is produced by a given quantity of a food. Calories are supplied by the carbohydrate, protein, fat, and alcohol in the food. Technically speaking, one calorie is the amount of heat needed to raise the temperature of 1 kilogram of water by 1 °C at 1 atmosphere pressure.
Why count calories?
Fact: When you eat more calories than you need, you gain weight. The wild card is determining what you need because there are so many variables. In general, an individual needs only the calories he is able to burn. You can maintain a healthy weight by matching the calories you take in to the calories you burn day-after-day, year-after-year. You can lose weight by taking in fewer calories than you burn.
Counting calories is a real eye-opener. Research shows that most people don't realize how many calories they eat. They don't see the extra calories that come from large portions and high fat foods.
As a weight loss method, calorie counting doesn't give you rules about what, when, and how much to eat. The only recommendation is to have a balanced diet of the foods you prefer within your calorie requirements. Calorie counting causes people to make adjustments to their food choices, portions, and physical activity prevent exceeding calorie goals.
How are calorie requirements derived for an individual?
Calorie requirements are determined by several factors, most important of which are size and body composition. Larger people with more muscle need more calories. Age and gender also make a difference, with men and younger people needing more calories than women and older people. Other factors, such as excessive thyroid hormone, fever and illness, and extremes in temperature, can raise calorie requirements temporarily. An individual's activity level also impacts his or her calorie requirements, but that is not a fixed factor because activity can change from day-to-day.
How many calories should I be eating in a day?
Assuming you are in good health, the answer depends on your height, weight, age, gender, activity level, and the amount of muscle you have on board. For instance, at moderate activity levels, a 30-year old woman who is 5'5" and 125 pounds needs about 2200 calories a day, while a 30-year old man who is 6'0" and 172 pounds, needs about 2800 calories a day. Calorie requirements should be based on a person's adequate weight rather than on a weight that is over or under the adequate range. A person's muscle mass is the wild card in determining requirements because it is difficult to measure muscle mass without special training and equipment. More muscle requires more calories. In order to lose weight, you should create a deficit of 500 - 1000 fewer calories than you need. To create that deficit, you have the options of eating less, moving more, or doing a little of each.
How much weight should I lose?
Ideally, you should lose enough weight to place you in the adequate weight range on the BMI chart, which is a BMI of 19 - 24.9. For example, for a 5'5" tall person, the adequate range is 114 - 144 pounds. The range account for differences in gender, frame size and muscle mass. In general, small-boned Asian and some Caucasian women should aim for the bottom of the range, while men and some large-boned and African people are better placed at the top of the range. Considerable variation exists among individuals regardless of race.
The rate at which weight should be lost is another issue. An average loss of 0.5 to 2 pounds per week is the clinical guideline to be compatible with good health. Health professionals measure success as a loss of 10% of body weight over six months.
What should I eat in a day?
You should eat a balanced diet with all of the food groups represented. After you have the necessary food servings, if you have calories left, you can spend them on "discretionary" foods that might be high in fat and sugar without many nutrients. Of course, you can spend your discretionary calories on wholesome foods as well. For great information about what to eat in one day, go to www.mypyramid.gov.
Read more in our library: What Is a Balanced Diet?
How did I gain 4 pounds in one day?
Temporary weight gain is most likely a result of water retention, which can be caused by eating too much sodium. Water is heavy: a gallon weighs 8.34 pounds. In the body, sodium is found in the tissues outside of the blood vessels. If sodium becomes too concentrated, water rushes in to lower the concentration. The result is puffiness, often seen in the fingers and ankles as gravity pushes water to the ground. To eliminate excess sodium and water, reduce dietary salt intake and drink plain water to flush out the system. In women, the hormones of the menstrual cycle can also cause sodium retention. Certain medications can cause water retention as well.
Do I have to eat three meals a day?
There is no law that says you have to eat three meals a day. You may eat two, four, five or more meals if you prefer. The three-meal plan follows the body's natural tendency to feel hungry about five hours after the last meal. If you choose to eat less often, you might become ravenous and be inclined to overeat. If you eat more frequently, your meals will have to be small to keep within your calorie requirements.
Why must I eat at least 1,200 calories a day when I want to eat less?
In order to get the daily food servings you need for a balanced diet, it takes about 1200 calories a day. With careful planning, you could have a balanced diet on 1000 calories, but the restrictiveness of a very low calorie level can lead to binging and weight cycling, which will take you further from your weight loss goal. What's more, very low calorie diets can cause excessive muscle breakdown and metabolic adaptations, which can drive down your calorie requirements. In the end, you'll need fewer calories to maintain a higher weight.
Should I be following a low carbohydrate diet?
Research shows that dieters who follow a low carbohydrate diet, like Atkins, lose more weight at first, but after one year, there is no difference in weight loss between dieters who follow low carbohydrate or low fat diets. Calorie control makes the difference. As long as you stay within your calorie requirements for weight loss, the specific ratio of carbohydrate to protein to fat is not so important as long as you get the nutrients you need and do not exceed the upper limits for saturated and trans fats.