People gain weight by consuming more energy than they burn, so consuming fewer calories, or energy, can help. However, other factors play a role, such as genetic factors, metabolism, hormones, the type of food you eat, your body type, and lifestyle.
This article will look at the reasons to lose weight, the most effective methods and medical interventions.
Here are some key points about losing weight. More detail and supporting information is in the main article.
- To lose weight, you must burn off more calories than you consume.
- A balanced diet and exercise combined are a healthful and effective way to lose weight.
- A sedentary adult aged 31 to 50 years should consume 2,200 to 2,400 calories or less each day.
- Crash diets may have short-term results but are unlikely to be successful in the long run.
- Sleeping for 7 or 8 hours a day may help with weight loss.
- Bariatric surgery should be a last resort.
Obesity affects more than one third of Americans.
The Centers for Disease Control and Prevention (CDC) estimate that currently affects more than 1 in 3 people in the United States, or 36.5 percent.
Why lose weight?
People lose weight for many different reasons:
- Appearance: They want to look fitter, more attractive or healthier, or simply feel more confident in their bodies.
- Confidence and body image: People who carry excess weight may feel self-conscious about it.
- Overall health: They want to become healthier, live longer, and avoid developing diseases associated with obesity and overweight
- For a specific condition or illness: People with sleep apnea or type 2 diabetes may find symptoms improve or disappear after losing weight.
- Fitness: People wish to become fitter, and to have more energy and stamina
- Sports competitions: Boxers, for example, may wish to lose weight so that they can remain within their weight category.
- Fertility: Fertility treatment has been found to be more effective among women with obesity and polycystic ovary syndrome (PCOS) who lose weight before treatment.
There are thousands of different diet plans on the market that make amazing weight loss claims.
Some are evidence-based, safe and effective, but others are not. Most health professionals, dietitians, and nutritionists agree that the best results tend to come from combining a healthful, weight-reduction diet with physical activity, especially in the long term.
You can click here to find out about eight of the most popular diets.
Proponents of many diets say they are extremely effective and require no effort at all. Unless they have been proven to be so in scientific studies, it is not possible to know how effective they really are.
The number of calories a person needs depends on their age, gender, and level of daily activity.
The number of calories per day you should consume to lose weight depends on several factors, including your sex, how much you want to lose, how quickly you want to lose it and your age.
Below are the daily calorie requirements for men and women, according to the US Department of Agriculture (USDA).
Daily recommended calorie consumption for males:
- Sedentary: 2,600
- Moderately active: 2,800
- Active: 3,000
- Sedentary: 2,400
- Moderately active: 2,600-2,800
- Active: 3,000
- Sedentary: 2,200-2,400
- Moderately active: 2,400-2,600
- Active: 2,800-3,000
- Sedentary: 2,000-2200
- Moderately active: 2,200-2,400
- Active: 2,400-2,800
Daily recommended calorie consumption for females:
Age 19 to 30 years
- Sedentary: 1,800 to 2,000
- Moderately active: 2,000 to 2,200
- Active: 2,400
Age 31-50 years
- Sedentary: 1,800
- moderately active: 2,400-2,600
- Active: 2,200
Age 51+ years
- Sedentary: 1,600
- Moderately active: 1,800
- Active: 2000 to 2,200
If you want to lose weight, you would have to consume less than the amounts listed above. The less you consume, the faster you lose. However, it is important to follow a healthy, well-balanced diet so that you do not become ill, or lose lean tissue (muscle). Ideally, you should check with a dietitian, nutritionist or your doctor.
In some regimes, dieters consume 1,200 calories per day if they are female and 1,500 if they are male. However, do not try to do this yourself without the supervision of a trained expert.
You need to make sure your carbohydrate, protein, and fat ratio is right for good health. Recommendations for carbohydrate intake vary, from 20 to 60 percent for losing weight.
A poor diet and malnutrition can occur regardless of calories. A meal plan should be balanced in terms of nutrients, too. A poor diet can lead not only to malnutrition, but also a low mood and loss of motivation. This can cause to dieters drop out before reaching their target weight.
When dieters have reached their target body weight, they should gradually increase their daily intake until they reach their "weight maintenance" figure.
A 2010 study showed that people who just reduce their daily calorie intake rarely lose much weight.
The researchers explained that natural compensatory mechanisms in the body reduce a person's physical activity as soon as calorie consumption drops. In other words, the body slows right down if you eat much less. Dieting must be combined with exercise.
Study leader Judy Cameron said:
"In the midst of America's obesity epidemic, physicians frequently advise their patients to reduce the number of calories they are consuming on a daily basis. This research shows that simply dieting will not likely cause substantial weight loss. Instead, diet and exercise must be combined to achieve this goal."
In response to a reduction in calories, the human's natural body mechanism goes into "conservation mode." Without exercise, there simply will not be much weight loss, they emphasized.
Sleep deprivation can increase weight gain.
Body weight control is much more successful if you can combine a well-balanced diet with regular exercise.
Crash diets may have positive short-term results, but they tend to have poor long-term success rates.
If you manage to sleep between 7 and 8 hours continuously in each 24 hour period, your body weight control will be more successful. Sleep deprivation or lack of sleep can make you put on weight.
In 2009, researchers combined the successful weight loss strategies of 6,000 individuals.
They came up with the following measures to prevent putting weight back on after losing it:
- Physical activity: Do at least 200 minutes each week of moderate-intensity exercise. This should be spread out over at least three days (do not do all the minutes in one go each week).
- Watching TV: Limit your TV watching to no more than 10 hours each week. Many people might find this recommendation particularly difficult to follow.
- Fat limit on diet: Make sure that no more than 30% of your nutritional intake is in the form of fat.
- Eat consistently: Resist the urge to overeat during weekends and holidays. Your food intake should follow a regular routine. Overeating not only upsets your routine, it most likely impacts on your metabolism.
- Breakfast: Never miss it. Breakfast helps stave off hunger later on in the day, and this can help prevent overeating and snacking.
- Monitor yourself: Keep a close check on what you eat and regularly weigh yourself.
Weight and health
Some health professionals and researchers disagree with focusing on weight loss when advising patients and clients. They believe that dieting and weight-loss efforts may lead to further weight gain and poorer health.
Instead, they suggest focusing on better health status, because this results in better body weight control over the long term.
Linda Bacon, of the University of California, Davis Department of Nutrition, said:
"Although health professionals may mean well when they suggest that people lose weight, our analysis indicates that researchers have long interpreted research data through a biased lens.
When the data are reconsidered without the common assumption that fat is harmful, it is overwhelmingly apparent that fat has been highly exaggerated as a risk for disease or decreased longevity."
A number of supplements are available that claim to help people lose weight.
- omega-3 products and fish oils
- chitosan, derived from shellfish
- green tea extracts
- some Chinese herbs
- bitter orange extract
According to the National Center for Complementary and Integrative Health (NCCIH), are not these are ineffective, and they are likely to have side effects.
Ephedra was used in weight-loss supplements in the past, but it has been banned because of safety concerns.
Further concerns include items such as "fat burners" being sold without approval from the Food and Drug Administration (FDA) and the fact that some herbal supplements may not contain exactly what the label says.
The NCCIH points out that approaches that focus on the mind and the body may help.
- mindful eating
They recommend finding a qualified and experienced instructor to guide you through these activities.
Bariatric surgery is performed on dangerously obese people.
Bariatric surgery, also known as weight loss surgery, is a surgical procedure which is carried out on people whose body mass index is high enough that it puts them at risk of serious complications.
It is only recommended if other weight-loss strategies have not worked.
The procedure involves either reducing the size of the stomach with a gastric band, or surgically removing part of the stomach.
In some cases, gastric bypass surgery is recommended, in which the small intestines are rerouted to a small stomach pouch.
After the procedure, the person's appetite is considerably reduced, and they cannot absorb or digest food as fully as before.
Bariatric surgery can be an effective way of reducing body mass index (BMI) for people with severe obesity, although research results for different procedures have not confirmed which type of surgery is best in each case.
The procedure has proven successful in to treating type 2 diabetes and reducing cardiometabolic risk.
It is important to aim for a body weight that is compatible with your height, age, and sex. This article may help you decide: What is my ideal weight?
When is weight loss bad?
In some cases, losing weight may not be the answer.
Weight loss happens when a person exerts more energy than they consume. This is called a negative energy balance. The body seeks out stores of energy, starting with fat, to make up the shortfall.
In a person with little fat, more muscle and lean tissue will be used up. This can lead to further health problems.
- a higher risk of osteoporosis
- reduced muscle mass and strength
- problems regulating body temperature
- a lower ability to resist infections
A severe loss of body mass can be life-threatening.
A number of genetic factors may influence how people gain weight, according to research published in the journal Obesity.
For the first time, scientists have uncovered a direct link between a gene and fat production in the body - a discovery that may hold the key to tackling obesity.