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How can I lose weight in a healthy way?
If you are carrying extra kilos, losing weight and keeping it off can be a challenge. Embracing healthy lifestyle habits is the key to not only losing weight, but looking after your health as well.
What is a healthy weight?
A healthy weight for your height is one that does not increase your risk of health problems. Carrying too much weight (being overweight or obese), or carrying too little (being underweight) can increase your risk of a range of serious health problems.
Energy and weight
The energy in food is measured in kilojoules or calories (1 calorie = 4.2 kilojoules). Foods vary in the amount of energy they provide. For example, vegetables tend to be low in energy and high in fibre and nutrients the body requires. Proteins and carbohydates have roughly the same amount of energy per gram, but fats and alcohol are higher in energy.
Metabolism describes the chemical processes that occur inside the cells in your body in order for the body to function. Your basal metabolism is the amount of energy you need when you have not recently eaten and are resting. Age, sex and body composition (such as amount of muscle) change your basal metabolism, but it is likely to be more complicated than that. Genetics, hormonal fluctuations, sleep and stress may also have an effect on your basal metabolism.
Physical activity uses extra energy. The more vigorous the exercise (such as running), the more energy the body will use, although all activities, such as housework, walking to the shops - even standing still - contribute to the amount of energy your body uses every day.
With high-energy foods, you can take in large amounts of energy very quickly, while it takes much more time and effort to work off that energy.
Even eating small amounts of extra energy on a daily basis can eventually add up to carrying quite a lot of extra weight if you do it over a long period of time.
Ways to lose weight
Lifestyle changes such as consuming less energy and being more physically active are the key steps to losing weight. They enable you to create a situation where your body uses more energy than you take in. This is called an energy deficit. Over time, this means that the body will burn the fat it has stored.
In most cases, it is recommended that you try to lose weight gradually. The Australian Dietary Guidelines  for the management of being overweight or obese recommend aiming for an energy deficit of 2500 kilojoules per day, although this may vary, depending on individual needs.  Your doctor or a dietitian can provide tailored advice for your situation.
Sudden and major lifestyle changes can be difficult to maintain long-term. This can mean that although you lose more weight initially, you may find yourself regaining it quickly when you are no longer able to restrict your diet or be as physically active.
However, in some cases, more intensive measures such as very low-energy diets, medications and bariatric surgery may be considered for people if they:
- Have not been able to lose weight or prevent weight gain, despite persisting with lifestyle changes;
- Are obese and have a lot of weight to lose, and;
- Have related health problems such as type 2 diabetes.
These measures are always recommended in conjunction with making long-term changes in the way you eat and how active you are. If you do not make these lifestyle changes:
- You may experience serious side effects, and;
- You may find that once the treatment ends, you will regain weight.
Eating for weight loss
Even though reducing the amount of energy you consume is very important for weight loss, it is also important that your body receives the nutrients it requires.
The Australian Dietary Guidelines provide advice on how to eat a healthy diet and this applies even when you are trying to lose weight. It is important to remember that depending on your size and how physically active you are, you may need more or less food than other people.
Habits that can help you eat healthily and lose weight include:
- Understanding the principles of healthy eating, including eating a wide range of nutritious foods each day;
- Learning the energy content of various foods and beverages you consume. Many foods list their energy content on the nutrition information panel on the packaging;
- Being aware of portion (or serve) sizes of foods, particularly with high-energy foods;
- Limiting your portion sizes. Use smaller plates and bowls for foods and tall, thin glasses for drinks;
- Cutting down, rather than completely cutting out, foods that are high in sugar and fat. You do not have to deny yourself your favourite treats entirely, but reducing how much and how often you eat them can help;
- Drinking plenty of water;
- Limiting beverages that contain high amounts of energy such as soft drinks, fruit juices and alcoholic drinks;
- Filling up on foods that are high in nutrients and dietary fibre, but low in energy, such as vegetables and fruit;
- Being aware of situations where you tend to eat and drink more (such as when you are eating out or at a party). Strategies such as pacing yourself, ordering smaller or healthier meals, sipping water between drinks and positioning yourself away from the all-you-can-eat buffet can help to prevent these occasions from derailing your weight-loss efforts, and;
- Being mindful of why you eat. Many people eat for reasons other than hunger. If you can identify emotional triggers that make you reach for comfort food, you may be able to find ways other than eating to deal with them.
Very low-energy eating plans
Very low-energy eating plans in which people consume a very low number of kilojoules per day are generally only considered for adults who:
- Have a BMI of 30 kg/m  or greater, or;
- Have a BMI of 27 kg/m  or greater and have other related health problems such as type 2 diabetes.
Very low-energy eating plans generally involve substituting meals with meal replacements that contain important nutrients, but have low levels of energy. They are recommended to be followed for a limited time and only under medical supervision.
Very low-energy eating plans can have side effects including constipation, gallstones, gout, headaches, dizziness, tiredness, loss of hair and dry skin. They can also reduce the density of your bones which, over time, can lead to osteoporosis.
Restricting your food intake severely is very difficult to maintain and is strongly associated with binge eating. It can also lead to a reduction in your metabolism. As a result, once you go off the eating plan, you may find that you put on weight rapidly.
Fad diets or crash diets that severely restrict energy intake may also cause these types of problems.
Dietary supplements are widely used for weight loss, but in general there is little evidence available on how safe or effective they are. Some supplements such as ephedra (which is no longer available in Australia) have been shown to have serious side effects. Supplements and herbs can interfere with prescription medications, so it is important that your doctor knows about any supplements that you are taking.
Monitor your weight
Regularly measuring your weight and waist circumference is a good way of monitoring how you are going with your weight-loss efforts. It is important to remember that your daily weight will fluctuate, so it can be better to monitor your weight for a longer interval, such as weekly or twice weekly.
Physical activity is activity that gets you moving your major muscle groups; anything from walking and doing household chores through to running and cycling. Both your day-to-day activities, such as commuting to work or gardening, and structured activities such as having a game of tennis or going to the gym, can count towards your daily activity levels.
Evidence shows that physical activity on its own is not very effective at helping people to lose weight; however, when combined with healthy eating changes, it can assist with both weight loss and preventing weight regain. It offers many potential health benefits, even when it does not lead to weight loss.
The Australian Physical Activity Guidelines for people aged 18-64 make recommendations on how much physical activity people need to do in order to enjoy health benefits. 
Firstly, the guidelines recognise that any level of physical activity is better than none. If you have any medical conditions that may make physical activity unsafe, your doctor can advise on what kinds of activities may be suitable for you. If you have been inactive for a while, slowly increasing your level of physical activity can help you to ease your way back into being more active.
The guidelines recommend that people carry out:
- 150-300 minutes a week of moderately vigorous physical activity (exercise that requires effort, but is not so hard you cannot talk, such as brisk walking);
- 75-150 minutes of vigorous physical activity (exercise that requires enough effort that you are breathing hard), or;
- A combination of moderate and vigorous physical activity.
It is more effective to spread your activity over most or all days of the week, rather than getting all your physical activity in on one or two days of the week.
Muscle strengthening exercises are recommended to be incorporated into your routine two days a week. Although building lean muscle mass can increase your weight, it does not increase the amount of fat you carry and so does not increase your risk of health problems. It can also help to make you stronger, boost your metabolism and, over the long term, maintain a healthier weight.
You may find fitting in more physical activity easier if you:
- Look for opportunities to be more active as you go about your day. Take the stairs instead of the lift, or walk rather than drive the car when you have short distances to go;
- Consider active commuting, such as cycling rather than driving;
- Join in with other people. Hook up with other cyclists for a regular ride, join a sports team, attend a regular gym class, or just make a regular walking date with a friend;
- Find activities you enjoy that are convenient and easy for you to do;
- Mix up your activities. You can walk one day and try something more vigorous the next, and;
- Remember that being active does not have to be expensive. Walking is a low-impact exercise you can do almost anywhere with just a pair of comfortable shoes.
Reduce sitting time
Sedentary time is time spent sitting. When you are sitting, your body uses less energy because major muscle groups, such as those in your legs, are not having to work as hard as when you are standing and being active.
The Australian Physical Activity Guidelines recommend limiting prolonged periods of sitting and getting up frequently to break up the time you spend sitting. 
Psychological therapies and counselling
Psychological therapies are sometimes referred to as 'talking therapies'. They may be helpful if issues such as stress, depression or anxiety are contributing to unhealthy eating habits. Psychologists, counsellors or doctors may be able to provide advice on strategies that can help you to change your behaviours and maintain your new habits.
Prescription medications may be considered for adults who:
- Have a BMI of 30 kg/m  or greater, or;
- Have a BMI of 27 kg/m  or greater and have other related health problems such as type 2 diabetes.
Use of these medications is usually only recommended for a limited period of time and must be closely monitored by your doctor. They are not a substitute for making changes in what you eat and being physically active, and they are not suitable for everyone. Your doctor can discuss whether they are suitable for you.
Orlistat can assist with weight loss by interfering with the action of enzymes in your digestive system that break down fat. This means that some of the fat in the food you eat passes through the body undigested.
Side effects with orlistat are common, particularly if you eat high-fat foods. They can include:
- Oily, loose stools;
- Flatulence (breaking wind);
- Frequent bowel movements, and;
- Loss of bowel control and leakage of stools.
Phentermine works by reducing appetite and may also help to increase the amount of energy your body uses up. It is generally only prescribed for a short time (for example, three months) to assist with weight loss as you change your diet. It can cause a range of side effects such as high blood pressure (hypertension), difficulty sleeping (insomnia) and a racing heartbeat.
Obesity (bariatric) surgery
Bariatric surgery alters the digestive system in order to reduce the amount of food the stomach can hold and/or reduce the amount of energy and nutrients that can be absorbed in the small intestines.
Obesity surgery may be considered for adults who:
- Have a BMI of 40 kg/m  or greater, or;
- Have a BMI of 35 kg/m  or greater and have other related health problems such as type 2 diabetes.
Following surgery, you will need to follow your doctor's instructions regarding regular check-ups, sticking to a strict eating plan, taking vitamin and mineral supplements and performing regular physical activity. In most cases, you will need to do this for the rest of your life.
The amounts of weight that people can lose with obesity surgery are often large (around 20-30% of your total body weight if you have a BMI of 35 kg/m  or more).  However this varies between people and some people do regain weight over time.
- Laparoscopic adjustable gastric banding (commonly known as 'lap band') - an adjustable plastic band is placed around the stomach to reduce its size;
- Sleeve gastrectomy - the stomach is divided to reduce its size;
- Gastric bypass - the stomach size is reduced and then reconnected directly to the small intestine further down, which bypasses most of the stomach and upper portion of the small intestines, and;
- Biliopancreatic diversion - the stomach is divided to reduce its size, then reconnected directly to the small intestine further down. This helps to significantly reduce fat absorption.
Your surgeon can discuss the potential benefits and side effects of each technique and which one might be most suitable for you.
Weight loss is a complex process. For most people, limiting the amount of energy that is consumed daily and ensuring an appropriate amount of physical activity is done will result in weight loss. If you have tried this and have not succeeded in controlling your weight, or if your have medical conditions that relate to your weight, then other measures such as medications or surgery may be appropriate. Whatever you do, make sure it is not a chore. Having fun is often the key to success.