What Affects Your Weight?
Your weight is affected by three major factors: your genetic
makeup, what you eat, and your activity level.
Genetics
Your genetic makeup affects your
resting metabolic rate, your appetite and point of
satiety (feeling full), your weight range, how your body fat is distributed,
and possibly the tendency to be active or inactive.
- Resting metabolic rate (RMR). RMR is the
rate at which your body uses energy (calories) at rest, and therefore, it
affects your total energy needs. Some people have higher RMRs than others
(based on heredity, height, body composition, and age). A lower RMR makes it
easier to gain weight. Your RMR can change slightly in response to certain
conditions. For example, starvation or very low-calorie diets will decrease
your RMR. Overeating increases RMR, as do fever and severe physical stress,
such as recovery from surgery or from extensive burns.
- Body signals. Hunger, satiety, and appetite are body
signals that tell you how much to eat. These signals can be influenced by your
environment or ignored for short periods of time. However, they are powerful
hormonal drives, and trying to ignore them for a long period of time (as in
dieting behaviour) can cause you to become obsessed with food.
- Fat
distribution. Your weight distribution changes as you age. Aging leads to
decrease of muscle mass and an increase in fat. Men store more fat in the
abdomen as they age, and women store more fat in the hips and thighs. Repeated
weight loss and weight regain can change the proportion of fat to lean tissue
in your body and actually increase your percentage of body fat.
Nutrition
A balanced,
healthy diet includes lots of fruits, vegetables,
whole grains, protein (lean meats, eggs, legumes, and nuts), and low-fat dairy
products. This supplies your body with the nutrition it needs and lowers your
risk for some diseases, like heart disease, some cancers, and
osteoporosis.3 In addition,
you will generally feel better and have more energy if you practise healthy
eating habits.
The
average
Canadian diet
contains too many
calories and too much fat, cholesterol, animal
protein, salt, alcohol, and sugar. Many of us don't get enough whole grains,
fruits, and vegetables.
It can be hard to make healthy food choices.
Factors that influence our food choices include lack
of time to cook and easy access to fast foods and packaged snacks. In addition,
sometimes foods that seem like a healthier alternative may not be. For example,
a low-fat cookie may have less fat, but it is usually high in sugar and often
has the same number of calories as a regular cookie. Potato chips labelled
cholesterol-free are still a high-fat, high-calorie, low-nutrient snack
food.
People who eat regular meals tend to be more successful at
maintaining a healthy weight than people who eat on an irregular schedule or
skip meals. More importantly, planned meals are usually more nutritious than
meals grabbed on the go or at the last minute. Also, skipping meals may make it
more likely that you will overeat at the next meal or eat a
less-than-nutritious snack.
Physical activity
Physical activity is very important for preventing obesity and
improving health. Staying active is the best way to maintain a healthy weight
that's right for you. Regular physical activity (moderate-intensity or
vigorous-intensity) can improve blood
cholesterol and
triglyceride levels,
reduce blood sugar, improve other indicators of disease, and increase your
fitness level. Moderate-intensity physical activity is equal to a brisk walk.
If you're depressed, regular physical activity can help lift your
mood. It can also boost your self image and self-esteem.
Even if you are overweight or obese, you will benefit from being
more physically fit. In a study of more than 25,000 volunteers, researchers at
the Cooper Clinic found that a person's fitness level was a stronger predictor
of death than body weight. Men in the study whose
BMI classified them as overweight or obese but who
were physically fit had a lower death risk than men who had a BMI in the
recommended range but were not physically fit.1