What is Obesity?
"Obesity" refers to an excess amount of body fat. It develops when the number of calories (energy) consumed in food and beverages exceeds the number of calories that the body burns to function. There are also no formal standards that define obesity based on the amount or percentage of a person's total body fat. A common way to screen for obesity is the body mass index.
What Is the Body Mass Index?
The Body Mass Index (BMI) is a tool used to measure weight as it relates to height. To calculate your BMI, you divide your weight (in kilograms) by the square of your height (in metres). So, for example, if you weigh 70 kg and are 1.75 metres tall, your BMI is 70/(1.75 x 1.75), which is 22.9. BMI has its limits. It does not assess body fat or muscle directly. Men and women can have the same BMI but different body fat percentages. As a rule, women usually have more body fat than men. For Indian individuals overweight is defined as a BMI of 23 to 24.9 and obesity as a BMI greater than or equal to (≥) 25. BMI ≥ 40 is known as "extreme obesity" or "morbid obesity".
If two overweight or obese people have the same BMI, the person with a bigger waist circumference will be at a greater risk of developing health problems due to their weight. This is because it is not just whether you are carrying excess fat but where you are carrying it. The risks to your health are greater if you mainly carry a lot of extra fat around your waist ('apple-shaped'), rather than mainly on your hips and thighs ('pear-shaped'). The easiest way to measure your waist circumference is to place the tape measure around your waist at belly button level.
As a rule for a man: If you have a waist measurement of 90 cm or above, the risk to your health is increased. As a rule for a woman: If you have a waist measurement of 80 cm or above, the risk to your health is increased.
What are the health risks of being overweight or obese?
Type 2 diabetes, hypertension (high blood pressure), High cholesterol or triglyceride levels, Coronary heart disease, Stroke, Fertility problems, Complications in pregnancy (including an increased risk of high blood pressure during pregnancy, diabetes during pregnancy, preterm labour, caesarean section), Stress incontinence (leaking urine when you are, for example, laughing, coughing, etc), Gallstones, Gout, sleep apnea (excessive snoring, daytime sleeping), nonalcoholic steatohepatitis (fatty liver disease), lower extremity edema (swelling of the legs and feet) and skin compression (ulcers).
What is the cause of being overweight or obese?
In some respects, the cause sounds quite simple. Your weight depends on how much energy you take in (the calories in food and drink) and how much energy your body uses (burns) up:
a. How much you eat and drink?
Many of the foods that people eat are those higher in calories (particularly fatty and sugary foods), so-called energy-dense foods. Food portion sizes in general have increased. There has also been a tendency to eat out more over recent years. If you eat out, you are more likely to eat food that is more energy-dense than you would eat at home. The amount of processed foods and ready-made meals available has also increased in response to our busy lives. What you drink is also important. Alcohol and sugary drinks contain a lot of calories. Even fresh fruit juices that you may think are healthy can make up a significant part of your daily calorie intake if you drink too much of them.
b. Your physical activity levels
Fewer people these days have jobs which are energetic. The variety of labour-saving devices and gadgets in most homes and the overuse of cars, means that most people end up using up much less energy compared with previous generations. A lack of physical activity by many people is thought to be a major cause of the increase in obesity in recent years.
You are more likely to be obese if one of your parents is obese, or both of your parents are obese. This may partly be due to learning bad eating habits from your parents. But, some people actually inherit a tendency in their genes that makes them prone to overeat. So, for some people, part of the problem is genetic. However, if you do inherit a tendency to overeat, it is not inevitable that you will become overweight or obese.
d. Medical problems
Less than 1 person in 100 obese people has a 'medical' cause for their obesity. For example, conditions such as Cushing's syndrome and an underactive thyroid are rare causes of weight gain. Women with polycystic ovary syndrome may also be overweight. Some medicines such as steroids, some antidepressants and sodium valproate may contribute to weight gain.
What are the benefits of losing weight and how much weight should I lose?
As explained above, many diseases are more common in obese and overweight people and you are less likely to develop them if you lose some weight. If your BMI is between 25 to 35, much of the health benefits come with losing the first 5-10% of your weight. If your BMI is more than 35, you will probably need to lose between 15-20% of your original weight to have sustained improvements in these health problems and other health benefits.
How do I know if my weight is already affecting my health?
If you are worried that you are overweight or obese, you should discuss this with your practice nurse or doctor. They may be able to determine if your weight is already affecting your health.
How can I lose weight?
Some people lose weight by strict dieting for a short period. However, as soon as their diet is over, they often go back to their old eating habits and their weight goes straight back on. Losing weight and then keeping it off, needs a change in your lifestyle for life.
- Motivation is crucial: no weight loss plan will work unless you have a serious desire to lose weight.
- Monitor your current food intake: Keeping a detailed diary of everything that you eat and drink over an average week is more helpful.
- Aim to lose weight gradually: it is best not to lose weight too fast. Aim to lose an average of 0.5 to 1 kg per week.
- Set clear goals with a realistic timescale: In most cases, health benefits can be gained from losing the first 5-10% of your weight.
Increase your physical activity levels
It is recommended that all adults should aim for 150 minutes of exercise a week. One way to do this is to do 30 minutes of moderate-intensity exercise for five days of the week. Moderate physical activity includes: brisk walking, jogging, dancing, swimming, badminton, tennis, etc. In addition, try to do more in your daily routines. For example, use stairs instead of lifts, walk or cycle to work or school, etc. Avoid sitting for too long in front of the television or a computer screen. Take regular breaks whilst working Build your exercise levels up gradually.
Monitor your behaviour and progress
You can use the same diary to to monitor your eating during your weight loss and to keep a track of your physical activity levels as well. It is also important to weigh yourself regularly to monitor your progress. Once weekly is recommended. However, don't be disheartened by minor weight increases or levelling off for a few days. Look for the overall trend over several months.
Get help and support
Ask your doctor for advice. A referral to a dietician may be helpful. One-on-one counselling or group counselling may be available. Ask about groups or programmes to increase your physical activity levels.
Treatment with medication to help with weight loss
Medication to help with weight loss may be an option for some people who want to lose weight. However, there are no wonder drugs available. Lifestyle changes to improve diet and increase physical activity are still important.
Surgery to help with weight loss
This may be an option if you are very obese. However, surgery is usually only offered if you have already tried other ways to lose weight which have not worked (including diet, increasing your physical activity levels and medicines). Surgery usually has very good results and most people do lose a lot of weight. However, this is specialist surgery and it is a major undertaking. Surgery to help weight loss is called bariatric surgery.
Keeping the weight off
To keep your weight off, it is important that you make permanent changes.
- Keeping to a healthy diet
- Exercising regularly
- A change for the whole household
Can overweight and obesity be prevented?
Yes. You can help to prevent becoming overweight or obese by:
- Following the healthy eating
- Doing 150 minutes of physical activity
- Spending less time being sedentary (for example, less time in front of your computer or watching TV).
- Weighing yourself from time to time
- Encouraging a healthy lifestyle for your whole family.