Recently a number of over the counter anti-obesity drugs such as Alli have become available which can help dieters help lose upto 50 percent more weight, compared with diet and exercise alone. Orlistat (sold over the counter and without a prescription as Alli) is a lipase inhibitor. These medications work by preventing the enzyme (lipase) in the gut from breaking down dietary fats into smaller molecules that can be absorbed by the body.
As a result the fat absorbed from food decreases by about 30% and is instead expelled from the body through bowel movements. Because of the way Alli works people who use it are advised not to eat more than 15 grams of fat with each meal. Eating greater amounts of fat will cause unwanted effects such as urgent bowel movements, diarrhoea and gas with oily spots.
While there is evidence to demonstrate that products such as Alli can help lose weight, this is estimated to be around 3-5 pounds over the course of a year, compared to around 8 pounds you could be expected to lose from undertaking regular exercise and adopting a balanced diet.
In addition once a person stops taking the medication in most cases the weight is regained. Orlistat also decreases the absorption of certain fat-soluble vitamins, so it is advisable that you would also need to take a vitamin supplement to prevent possible nutrient deficiencies.
Given the embarrassing nature of the side-effects, the short term effectiveness of the approach, not to mention the cost, individuals should think carefully about using such products and should never substitute them for the most effective and preferred approach – regular exercise and a balanced diet.