KNOW | UNDERSTAND | ACT
When people consume more calories than they use in the course of daily life and physical activity, they put on weight. Being overweight or obese means that you are carrying excess weight that can negatively affect your health. The battle of the bulge has become a worldwide phenomenon, but excessive weight gain and obesity is still predominately a Western problem. And one that Canada shares: Nearly 60% of Canadian adults, or 14.1 million people, are classified as overweight or obese. With modernization has come processed foods, sedentary lifestyles, and people struggling to manage their weight.
When you’re overweight or obese, your body is chronically out of balance. You take in more energy, in the form of calories, than you expend. This excess energy is stored as fat.
Obesity alters you cardiovascular disease (CVD) risk profile, negatively impacting the structure of your cardiovascular system and the very functioning of your heart. And it’s not just how much you weigh that matters but where you carry your excess weight. People who store fat around their stomachs have a higher risk for CVD and diabetes than those who carry it around their hips.
Obesity accounts for 20% of the risk associated with heart attack. It is a an important public health concern as it increases the risk of numerous other chronic health issues — type 2 diabetes, hypertension, and certain cancers.
People who are classified as obese are four times as likely to have diabetes, three times as likely to have high blood pressure, and two times as likely to have heart disease.
Causes of Obesity
Excess weight is the result of biological, environmental, and behavioural factors, but, ultimately, it’s a matter of eating too much food and not getting enough physical activity. Sedentary lifestyles combined with overeating leads to weight gain. Examples of trends that influence an individual’s weight include:
- Inactivity (reduced energy expenditure)
- Stressful and demanding situations
- An occupation with few physical demands
- Inexpensive, fat-laden foods
- Large portion sizes
- Easy access to high-calorie foods
Most people’s body weight fluctuates only slightly over the course of a year. But even a small amount of overeating combined with decreased activity can cause weight gain over time. The calories you fail to burn are stored as fat by your body. When substantial overeating is sustained over a long period of time, obesity can result.
Compared with the complexities of weight gain, the logic of weight loss can seem relatively straightforward:
- To lose weight, you must burn more energy than you take in.
- One pound of body fat equals 3,500 calories.
- To lose 1 pound a week, you must expend 3,500 calories by reducing your calorie intake and increasing your activity level.
Genetics is why 25% to 30% of people are overweight. Genes can be responsible for reducing your threshold for weight gain. If you have a family history of obesity, you are more likely to be overweight. The tendency toward obesity based on family history looks like this:
- People with two obese parents have an 80% chance of becoming obese themselves.
- Those with one obese parent have a 50% chance of obesity.
- If neither parent is obese, there is only a 10% chance of obesity.
However, genetic factors contribute to only part of the risk of being overweight or obese, and healthy lifestyle choices can counteract genetic effects.
People tend to put on weight as they age because their metabolisms slow down. The aging process causes the body to become less efficient at regulating the intake of energy. Essentially, the signals that regulate metabolism (calorie usage) change in older people.
Weight gain can be a complicated process. While it’s no mystery that big plates of french fries and buttery pastries can make you fat, the causes of weight gain aren’t always obvious.
You can gain weight when you experience added stress and when you don’t get enough sleep, partly because you might be using food as a coping mechanism. But another reason is your body releases chemicals that allow for more efficient fat storage.
Other reasons people put on weight:
- Some prescription medications that treat depression, migraines, diabetes, and blood pressure can cause minor weight fluctuations or as much as a 10-pound weight gain per month.
- Certain medical conditions, most commonly hypothyroidism, can decrease your metabolism and cause weight gain.
- Menopause can cause women to put on weight in their midsections, when prior to menopause, greater stores of estrogen encouraged fat accumulation in the lower body.
Associated health risks
Excess weight, particularly obesity, affects all systems of the body, creating a heightened risk for a range of diseases and conditions, including premature death. It is important to recognize any weight-related health conditions and address them as soon as possible.
Being overweight or obese puts you at risk for any of the following conditions:
- Coronary heart disease
- High blood pressure
- Pulmonary hypertension and increased risk of congestive heart failure
- High cholesterol
- Abnormal lung function
- Type 2 diabetes
- Metabolic syndrome (high blood sugar, high cholesterol, and high blood pressure)
- Cirrhosis of the liver
- Low back pain
- Cancer — colorectal and prostate in men; breast and ovarian in women
- Kidney abnormalities
- Menstrual and ovarian abnormalities
- Gallbladder disease
Body composition analysis is an important tool used to assess the degree to which a person is overweight or obese. It identifies the amount of lean body tissue (fat-free mass — muscle, bone, organs) as compared to the proportion of accumulated fat a person has. Because excess body fat represents a key cause of preventable disease, body composition analysis is part of most medical evaluations.
Two common body composition analysis tools are:
- Dual energy X-ray absorptiometry (DEXA), which is a body-scan test used to measure bone density, but it also measures body fat percentage and pinpoints exactly where your fat is located.
- Hydrostatic weighing, which essentially weighs you underwater. Because fat is lighter than water, the more fat you have, the more you’ll float.
In addition to body composition analysis, there are two other screening tools for gauging whether a person is overweight or obese: body mass index (BMI) and waist circumference measure. These are less direct measures of body fat but they are simple and considered accurate indicators.
Body mass index (BMI) is an indirect measure of body composition that takes into account your height and weight. BMI is a globally accepted tool for determining whether a person is overweight or obese. This value is obtained through a simple formula: weight (kg)/height (m)2. To get a sense of how the values are categorized, see the BMI Table below. Special consideration should be given when applying the BMI to children, who are not yet fully developed; naturally lean individuals; and people with especially muscular builds. Use this interactive BMI calculator to determine your body mass index.
|Obese category I||30.0-34.9 kg/m2|
|Obese category II||35.0-39.9 kg/m2|
|Obese category III||≥40.0 kg/m2|
Waist circumference is a measure that is often used in combination with the BMI. It serves as an indicator for the presence of abdominal fat. An overabundance of abdominal fat is referred to as apple-shaped, or “android,” obesity, in men. Women tend toward pear-shaped, or “gynoid,” obesity. Excess fat around the abdomen increases your risk for CVD, type 2 diabetes, breast cancer, and gallbladder disease. In general, the risk of developing health problems rises as waist circumference increases above the cut-off points listed in the chart below.
|WAIST CIRCUMFERENCE IN WOMEN|
|CAUCASIAN||< 35in (88 cm)|
|EUROPEAN||< 31.5in (80 cm)|
|JAPANESE||< 35.4in (90 cm)|
|SOUTH ASIAN||< 31.5in (80 cm)|
|SOUTH & CENTRAL AMERICAN||< 31.5in (80 cm)|
Lifestyle changes can help you lose weight and keep it off, bringing a range of health benefits, such as:
- Lower blood pressure and management of high blood pressure
- Lower levels of triglycerides and total cholesterol (forms of fat in the blood)
- Improved lung function
- Control of blood sugar (increased insulin sensitivity)
- Improved quality of life
- Improved mood
Prevention and Management Strategies
Being overweight or obese must be treated as a chronic medical condition with dire health consequences, particularly as they pertain to the cardiovascular system. Preventing weight gain in the first place is always the best strategy. But when you’re overweight or obese and have committed yourself to a weight-control program, it is important to remember that slow and steady wins the race. In many cases, to be effective, weight-management must incorporate a wholesale change — essentially a new way of eating, for life. The focus should be gradual, consistent weight loss over a long period of time.
Tips for Healthy Weight Management
As you begin your weigh-control program, keep these pointers in mind:
- Post your goals where you can look at them often, and you’re more apt to stay motivated.
- Aim to lose weight slowly — .5 to 2 pounds (.25 to 1 kg) per week, and you’re more likely to keep it off.
- Remember that quick fixes do not work.
- Lose even 5% to 10% of your body weight — it is enough to improve your heart health.
- Weight-loss strategies should be enjoyable, practical, and fit your personal lifestyle.
Eat regular meals:
- Aim to eat three meals a day.
- Space your meals no more than four to six hours apart.
- Include healthy snacks.
Build an eating plan, not a "diet":
- Weight management involves initiating a lifelong eating plan; diets are temporary — they don't work.
- Calorie intake should not be less than 1,200 calories per day.
- Remember that how much you eat counts.
- Choose smaller meals and snacks.
- Don’t cut back too much. If you’re hungry, you’re more likely to overeat.
- It takes 15 minutes or more for your brain to receive the signal that you’re full. Eat slowly to avoid overeating.
Choose from all food groups:
- Include foods from vegetables and fruits, grain products, milk and its alternatives, and meat and its alternatives.
- A healthy meal contains foods from at least three food groups.
Keep a food journal:
- Keeping track of what you eat will help you pinpoint your problem areas.
- Use this information to set goals for making small changes in your eating patterns.
- Aim for 30 to 60 minutes of exercise most days of the week.
- Try weight-bearing exercise, such as walking, stair-climbing, and skiing. It expends the most energy and has the added benefit of building bone mass.
- Engage in non-weight bearing activities, such as cycling and swimming, which expend a lot of calories and are excellent forms of exercise, particularly if you have knee problems.
- Walk briskly. You will lose weight, sleep better, increase your energy, and improve your overall heart health.
- Work out with a group to increase your motivation and accountability.
Know the effects of getting and staying active:
- An exercise program can burn between 300-500 calories a day or 1,000-2,000 calories per week.
- Exercise helps reduce belly fat, which reduces CVD risk.
- Exercise can increase muscle mass, which will cause basal metabolic rate to rise and help you burn calories more efficiently.
Get your family and friends involved in helping you meet your goal. But most of all . . . be patient:
- Setbacks can happen to anyone trying to make a change in eating and activity patterns.
- It takes about six months of practicing a new skill or behaviour to make it a habit.
- Accept that slip-ups occur, get back on track, and don't give up.
Selecting a Weight-Management Program
Find or craft a weight-management program that:
- Allows you to lose no more than 2 pounds a week — slower weight loss means longer term results (Canada’s Food Guide may be adapted to support gradual and safe weight loss).
- Promotes a balanced diet that incorporates all four food groups as outlined in Canada’s Food Guide.
- Encourages a combination of physical activity and nutrition strategies.
- Provides for a maintenance stage to make sure you stick to it over the long haul.
- Addresses your individual needs.
- Emphasizes realistic lifestyle changes rather than special diets or expensive prepackaged foods.
- Does not require a long-term contract.
- Is delivered by health professionals (physician, nurse, exercise physiologist, nutritionist) who are qualified to provide appropriate lifestyle recommendations tailored to your needs.
A smart eating plan includes a wide variety of choices from the four food groups. The number of servings recommended for each food item varies according to the number of calories you need to maintain a healthy weight. The chart below provides serving guidelines for the main food groups based on daily calorie intake:
4 to 6
4 to 6
5 to 7
3 to 4
Grains and starches
5 to 6
6 to 8
8 to 9
Milk and alternatives.
Meat and alternatives
Fats and oils
4 to 5
5 to 6
Sweets and other foods
0 to 1
1 to 2
1 to 3
Avoiding Special Diets
It would seem there are nearly as many weight-loss programs as people who want to lose weight. A lot of these are legitimate and effective tools that promote gradual weight loss and healthy lifelong habits. Others are more diet than lifestyle-altering program, and they have the potential to cause serious health problems.
Low-carb diets restrict the carbohydrates you eat to less than 20 grams a day. The diet promotes the mobilization of fat to energy because without carbohydrates as an energy source, the body is forced to draw on fat reserves. However, the initial pounds that come off are merely from water loss and precious metabolically active lean tissue is lost.
Focusing largely on protein, these extreme diets are ineffective long-term options. High-protein diets, like their low-carb counterparts, promote the use of fat, rather than carbohydrates, for energy mobilization. The breakdown of fat in these diets are associated with processes that strain both the kidneys and liver, ultimately leading to dehydration.
Other reasons high-protein diets should be avoided:
- Eating protein alone, you can’t be sure you’re getting the vitamins and minerals you need.
- Protein food sources are often associated with cardiovascular disease and diabetes because they tend to be high in saturated fats.
- Electrolyte imbalances from excess water loss, which leads to fatigue and changes in blood pressure, often occur with these diets.
When all else fails, some people resort to very low calorie diets, in which they get as little as 800 calories a day. The guiding principal of these diets is appetite suppression. With so few calories, the dieter eventually no longer feels hungry. These diets incorporate the use of meal replacements, liquid meals, and high-protein food sources.
Reasons semi-starvation diets should be avoided:
- There is often significant loss of lean body mass — most alarmingly from heart tissue.
- The initial weight loss comes merely from water excretion.
- Insufficient carbohydrates are consumed, which the body needs for energy.
- Because such an extreme diet cannot be sustained, unhealthy weight cycling is often the result.