There is much more to weight loss than meets the eye.
In fact, weight loss is associated with multiple health benefits, and may be the single most important thing you can do to improve your health (if you are overweight).
A recent review article in the magazine Annual Review of Nutrition provided a comprehensive overview of the health benefits of maintaining weight loss in the long term.
Rueda-Clausen et al. Health Benefits of Long-Term Weight Loss Maintenance. Annual Reviews of Nutrition, 2015.
The main aim of the review was to summarize the evidence for the risks and benefits of sustained weight loss.
How is Sustained Weight Loss Defined?
Before discussing weight loss maintenance, it is important to explain or define what that means exactly.
Several researchers have come up with their own definitions.
Wing and Hill defined sustained weight loss in the following way (1):
Sustained weight loss is an intentional weight loss that has been maintained for at least a year. Additionally, it is equivalent to at least 10% of the initial body weight before deciding to lose weight.
Further weight loss may have additional benefits.
It is Difficult to Determine the Health Benefits of Weight Loss
It can be very hard to determine the independent effects of weight loss on health.
There are a few reasons for this:
- Dietary changes: Weight loss is usually accompanied with changes in diet. Dietary changes may have very strong effects on health.
- Increased exercise: Weight loss is often associated with increased exercise. On its own, exercise may have immense health benefits.
- Calorie restriction: Negative energy balance, the main reason for weight loss, also has huge health benefits.
As a result, it very difficult (or impossible) to isolate the health benefits of the weight loss itself.
This is also the reason why weight loss strategies may have powerful effects on health outcomes, even though the weight loss itself is minimal.
Health Benefits of Weight Loss Maintenance
According to this review, losing weight and keeping it off may improve:
- Blood pressure: Losing weight may significantly improve blood pressure.
- Heart health: Weight loss has been associated with improved heart health and a reduction in risk factors.
- Type 2 diabetes: In people with insulin resistance (impaired glucose tolerance), weight loss may reduce the risk of type 2 diabetes or slow its progression.
- Blood sugar control: In people with type 2 diabetes, weight loss leads to better blood sugar control.
- Blood lipid profile: Weight loss causes improvements in the levels of blood lipids, reducing triglycerides and increasing HDL cholesterol.
- Osteoarthritis: Weight loss may reduce symptoms in people with osteoarthritis.
- Obstructive sleep apnea: Although weight loss rarely resolves obstructive sleep apnea completely, it may significantly improve symptoms.
- Obesity hyperventilation syndrome: Substantial weight loss can improve symptoms in people with obesity hyperventilation syndrome.
- Asthma: Weight loss maintenance may significantly improve asthma symptoms.
- Cancer: There is some evidence to indicate reduced risk of cancer with sustained weight loss.
- Quality of life: Health-related quality of life is significantly improved with weight loss.
- All-cause mortality: Studies suggest that weight loss may be linked to reduced risk of all-cause mortality.
Does Short-Term Weight Loss Have any Benefits?
Short-term weight loss has many benefits, similar to sustained weight loss.
The difference is that the health benefits of short-term weight loss are limited to the actual weight loss period. When people start regaining weight, health status may start worsening accordingly.
However, some studies indicate that short-term weight loss may have health benefits in the long term. This phenomenon is called the “legacy effect” or the “metabolic memory effect” (4).
Health Risks of Weight Loss
When it comes to health and nutrition, very few things are perfect.
There are usually some downsides, but many of them may depend on the individual or be limited to specific situations.
In addition, the weight loss method affects the potential health benefits and risks considerably.
Weight loss methods can be divided into three main categories:
- Behavioral: This group of weight loss methods includes diets and exercise programs.
- Pharmacological: This category includes weight loss methods that involve medications and supplements.
- Surgical: When other methods fail, liposuction and other surgical methods, such as gastric bypass, are occasionally used to treat obesity.
In general, behavioral weight loss methods are considered the safest approach, whereas pharmacological and surgical procedures are more risky.
Apart from potential complications associated with surgical methods and medications, weight loss may worsen symptoms in the following diseases:
- Non-alcoholic fatty liver disease: In people with non-alcoholic fatty liver disease, fast weight loss may worsen liver health.
- Gallbladder disease: Weight loss may increase the risk and severity of gallbladder disease.
Take Home Message
It is clear that intentional, sustained weight loss may have significant beneficial effects on various health outcomes.
However, it is difficult to isolate weight loss from other lifestyle factors that are unavoidably associated with weight loss. These include increased exercise, changes in diet and calorie restriction.
In certain individuals, weight loss may worsen liver health and gallbladder disease. However, other health benefits far outweigh possible adverse health effects.
In short, if you are obese and want to improve your health, losing weight may be the single most effective way to do that.