Can nutritional supplements work for weight loss? Here's a review of the evidence, and the top four supplements that are most likely to work for weight loss.

1. Coleus forskoohlii

Coleus is a herb used traditionally and currently in Ayurvedic medicine ⁽¹⁾.

Coleus activates a substance in the body called Cyclic AMP(cAMP), which stimulates cell metabolism. Cyclic AMP enhances insulin secretion, increases thyroid function and the breakdown of fat in cells ⁽²⁾

There have been a number of research trials testing Coleus and weight loss. A Japanese trial found significant decrease in body weight, BME and body fat from Coleus extract ⁽³⁾.  In 2005, American researchers observed that coleus caused  weight loss in overweight women  over a 12-week trial, with no difference in food intake compared to the placebo group. The participants taking coleus experienced less hunger and greater fullness ⁽⁴⁾.

Another study examined the effect of a Coleus extract on body composition, testosterone, metabolic rate, and blood pressure in overweight and obese men. Thirty subjects were studies for 12 weeks., and results showed favourable changes in body composition by significantly decreasing body fat percentage and fat mass compared with the placebo group. There was a trend toward a significant increase for lean body mass in the Coleus group. Testosterone levels were significantly increased in the Coleus group ⁽⁵⁾

Coleus is particularly helpful when under-active thyroid is preventing weight loss.

2. Green tea:

Green tea is thermogenic, which means that it increases energy expenditure and promotes weight loss.

A recent study reported that ingestion of green tea with extra caffeine increased resting energy expenditure by14% ⁽⁶⁾. Another study reported that ingestion of three 250 ml servings of green tea and calcium significantly increased 24 hour energy expenditure ⁽⁷⁾. In yet another study,  it was reported that ingestion of 300mg/day of green tea for 2 days significantly increased fat oxidation compared to controls ⁽⁸⁾.

Collectively these findings suggest that intake of green tea can increase resting metabolism, leading to a greater weight loss over time.

3. Fish Oil

Fish oil significantly lowers triglycerides, thereby improving heart health and protecting against cardiovascular disease ⁽⁹⁾

Current studies show that the Omega 3 fatty acids improve insulin signaling, and reduce fatty acid accumulation in the liver. Insulin resistance is a key player in weight gain and improving it's function will help burn carbohydrate more efficiently ⁽¹⁰⁾.

Another recent trial involving 324 men and women observed that the inclusion of fish oil along with and energy-restricted diet resulted in 1kg more weight loss after 4 weeks than did a similar diet without any fish oil supplementation ⁽¹¹⁾.

Fish oil is particularly helpful when insulin resistance is the underlying cause that is preventing weight loss.

4. Resveratrol

Resveratrol has been shown to inhibit leptin secretion from fat cells ⁽¹³⁾. This can significantly improve metabolic rate and weight loss.

In conclusion, the available research suggests that the most effective weight loss supplements are  those that increase resting energy expenditure, improve cellular metabolism, and improve insulin signaling.

Weight loss supplements are most effective when used as part of an individualised weight loss plan, including diet, nutrition, exercise, and hormone balance.

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