Chitosan is a polysaccharide compound present in the shells of invertebrates such as crabs, shellfish and other crustaceans. Chitosan supplement aids weight loss by inhibiting fat absorption. Obese individuals can take about 3 grams of chitosan daily. However, they are not recommended for people prone to shellfish allergy. The long-term effect of chitosan intake may increase the risk of constipation or diarrhea. By inhibiting fat absorption in the gut, in the long run, chitosan may increase the risk of deficiency of fat-soluble vitamins and calcium.

All types of tea, green, black or oolong, support fat loss by boosting thermogenesis. Tealeaves contain compounds called catechins that promote heat generation in the body by preventing degeneration of the hormone norepinephrine that regulates the thermogenesis process. In addition, catechins also retard growth of fat tissues. Besides catechins, caffeine present in tealeaves also elevates energy expenditure. To lose weight rapidly, an obese person should consume at least six cups of tea daily without any added sugar. The same result can be attained with supplements containing green tea extract.

The fruit of the Garcinia cambogia tree is a rich dietary source of hydroxycitric acid (HCA). HCA contributes almost 30 percent of the weight of the fruit. HCA obstructs fat absorption and storage, suppresses appetite and decreases food intake, thereby reducing body weight. Garcinia cambogia gradually lowers the body weight. By consuming 2.4 grams of Garcinia cambogia or supplement containing 1.2 grams of HCA, an obese person can lose about 1.3kg in three months. A high fiber diet might impair absorption of HCA. Diarrhea, vomiting and abdominal pain might occur after taking large amounts of Garcinia cambogia extract.

Synephrine alkaloids present in sour or bitter orange assist energy expenditure by boosting thermogenesis. Sour orange can suppress appetite, thereby reducing food intake. While small amounts of sour orange can be added to the daily diet of an obese person, prolonged intake or consuming large doses of sour orange extract may push up the heart rate and systolic blood pressure.

Ephedra, the key active component in ma huang (Ephedra sinensis) aids weight loss. The stimulant property of the herb helps to burn the unwanted fat reserve in the body by stimulating thermogenesis. Besides increasing calorie expenditure, ephedra also reduces appetite. 20mg of ma huang, which is equivalent to consuming 200mg of caffeine, can be taken daily, thrice a day. Ma huang should be taken for a brief period. Adverse side effects such as tremor, insomnia and even cardiac arrest might occur by taking the herb for a prolonged period.

Guggul gum is a resin extracted from Commiphora mukul, a tree of the myrrh species. An underactive thyroid gland is one of the key causes of obesity. When the thyroid gland fails to produce sufficient thyroid hormones, the metabolic rate of the body falls, slowing down energy expenditure, leading to weight gain. Guggul gum contains a compound called guggulsterone, which stimulates secretion of the thyroid hormones, thereby boosting the metabolic rate of the body. Moreover, by reducing the cholesterol and triglyceride levels in the blood, it improves the lipid profile. Obesity can be treated by taking 250mg of guggul gum thrice daily. Guggul gum may interact with thyroid medications and anticoagulants.

Conjugated linoleic acid (CLA) is a type of fat present in red meat and dairy products. Deficiency of CLA, ironically caused by a low calorie diet, is believed to increase the risk of obesity by inducing conversion of dietary fats into physical fats. CLA aids transportation of glucose to the muscle cells, thus inhibiting conversion of unused glucose into fat. In addition, CLA is needed for supplying fats to the connective tissues and muscles, where fat is used as fuel. 4.5-gram of CLA supplement can be taken daily.