Fat burners are used by people who wish to lose weight.

What are ‘fat burners’?

Fat burners are products containing nutritional supplements and/or herbal extracts. These products may comprise one specific active ingredient or are formulated from a number of active ingredients. Individual fat burning agents are claimed to have an action promoting weight loss, while the specific combinations are believed to have effects greater than the sum of the individual ingredients. A large number of supplements and herbal extracts are promoted as fat burners, including caffeine, carnitine, chromium, conjugated linoleic acid, ketones, green tea, Garcinia cambogian, Irvingia gabonensis, fucoxanthin and yohimbine.

How do fat burner work?

Fat burners are thought to work in a number of ways. Some fat burners increase the body’s metabolic rate (rate at which nutrients are broken down and used), and increase energy expenditure and energy levels. These products are sometimes referred to as ‘thermogenics’ because they produce heat by stimulating metabolism. Other ingredients stimulate the breakdown of fat, or prevent the body from absorbing fat. Fat burners may also suppress the appetite, leading to a reduction in the number of calories consumed. This may be achieved by ingredients that alter the balance of the body’s chemical messengers, and interfere with hunger messages to the brain. Appetite suppression may also be brought about by ingredients that provide fibre. Soluble fibre binds to fat, and promotes burning of sugar for energy instead of converting sugar to fat for storage. Insoluble fibre is not digested; by absorbing water and swelling in the intestine, it controls hunger by giving a ‘full-up’ feeling.

How to use fat burners

Fat burners may contribute to weight loss but should not be the only method used. It is recommended that they are used in conjunction with a healthy balanced diet and regular exercise. Fat burners should not be taken for life, but to achieve a target weight. Maintaining a healthy body weight is usually achieved through a balanced diet and exercising regularly, which also improve general health and wellbeing.

How effective are fat burners?

Fat burners are reported to be an effective means of weight loss. However, the amount of weight and speed of weight loss will vary among individuals according to how much weight they need to loose and to the formulation that they use. Notably, scientific evidence for the effects of these ingredients varies greatly and, in the main, is lacking. Claims may therefore be exaggerated and unsubstantiated.

Who can use fat burners?

Fat burners can be used by adults who want to lose weight. They are often taken by bodybuilders who wish to attain a specific muscular physique. Children and adults with other medical conditions, including disorders of the heart and intestine, should avoid fat burning supplements.

Side effects of fat burners

Many fat burners are available as non-prescription products. It is important to be aware that most fat burners have not been approved by the drug regulatory authorities, including combination products containing individually approved ingredients. Indeed, there is evidence that some of these products contain additional ingredients not stated on the label that may be of potential risk to health or that have safety warnings.

Regardless of whether the ingredients are natural, nutritional supplements and herbal extracts may have side effects as they interfere with the body’s natural functioning. Fat burners are associated with effects on the central nervous system (causing nervousness, anxiety, and mood swings), cardiovascular system (including increased blood pressure and heart problems) and liver (toxicity). Caffeine, for example, is a stimulant that can increase heart rate (potentially over working heart muscle), and cause alertness (preventing normal sleep patterns) and dehydration. There are even reports of death in people taking ephedra-containing supplements, which are now banned.

If you wish to achieve and maintain a healthy body weight, it is advisable to consult your doctor before using fat burners as this may best be achieved through a healthy diet and regular exercise.