Losing weight is a task that is more difficult than it seems and, even worse, many give up before the results are noticeable. Losing weight requires many factors and supplements could be a little help you need.
Next, we will mention some foods or substances classified as weight loss supplements and we will see if they are really useful or not for this task.
What are weight loss supplements?
In countries with high income, obesity represents one of the most prevalent conditions . In the US alone, more than two-thirds of adults are overweight or obese (1) . Approximately 15% of these adults have used weight loss supplements. (two)
In this sense, supplements are a heterogeneous group of substances that come in the form of capsules, pills, liquids, powders or bars. In general, these supplements work through different mechanisms, for example:
- They increase the burning of calories.
- They decrease appetite.
- They reduce the absorption of certain nutrients, such as fats, to prevent you from absorbing more calories.
Important: The scientific information that is available in this regard on these supplements is inconsistent, due to differences in the methodology and selected population.
In addition, even if the effect that an ingredient has is known, we do not know what effects it would have when its content is mixed (that is, more than two supplements in a single product). (3)
We should also mention, that burning calories through supplements is not enough to significantly lose weight . A healthier lifestyle involves sustainable eating patterns, moderate physical activity, and removing harmful habits (for example, smoking) from your life.
What are the best weight loss supplements?
Below we have listed the most commonly used weight loss supplements , explaining how they work and how effective they are (or not):
1. Caffeine
Among the most common ingredients is caffeine. Caffeine can be included directly in the supplement or caffeine-containing herbal extracts such as guarana ( Paullinia cupana ), kola (or cola) or yerba maté ( Ilex paraguariensis ) are introduced.
How does it work? It stimulates the central and sympathetic nervous system, heart activity, diuresis (promotes urination) and thermogenesis. In other words, it favors the burning of calories (energy) and the oxidation of fatty acids .
To highlight: The intensity of these effects is dose dependent . For example, 100 mg of caffeine can burn up to 9.2 kcal/hour, over 3 hours in an average healthy adult.
However, its effect may diminish as caffeine is consumed in large amounts. Both the FDA ( Food and Drug Association ) and the EFSA ( European Food Safety Authority ) state that the daily limit is 400 mg per day . (4) (5)
2. Green tea
Green tea ( Camellia sinensis ) contains caffeine, catechins (such as epigallocatechin-3-gallate), and flavonoids . For reference, a cup of green tea contains approximately 240-320mg of catechins and 45mg of caffeine.
How does it work? Through the same effects as caffeine and, in addition, it is suggested that green tea decreases lipogenesis (fat formation in our body), as well as decreases the absorption of fatty acids and carbohydrates .
Also, green tea contains very useful vitamins and minerals to maintain a healthy body.
You should know: Two meta-analyses, one published in Cochrane reviews (6) and in the American Journal of Clinical Nutrition (7) , found that this product has modest but significant effects on metabolism and weight loss.
3. Green coffee
Before the roasting process, the coffee beans are green and have a higher content of chlorogenic acid . Of course, the product contains caffeine, although you can find the decaffeinated form. How does it work? Chlorogenic acid from green coffee has the following effects: (8)
- Inhibition of enzymes responsible for lipogenesis.
- Regulates glucose metabolism, inhibiting its absorption.
To highlight: Most clinical studies have been in murine (rodents) and very few in humans. The documented effect is modest, but significant. However, studies in humans demonstrate methodological flaws . (9)
4. Glucomannan
It is a type of soluble fiber , extracted from the root of the konjac plant , native to countries in Southeast Asia. It has an osmotic effect, capable of absorbing 50 times in water, increasing satiety in people and decreasing the period of gastric emptying.
Note: In various studies, the effects of glucomannan on blood lipid and glucose levels are mixed. In a few studies, significant body weight loss was observed (10) , while a meta-analysis stated that no significant effect was observed. (eleven)
5. Raspberry Ketone
It is an aromatic compound, which has been extracted and marketed as a supplement that helps to lose weight by burning calories and fat .
In an in vitro study with mice, the supplement did aid weight loss through fat oxidation and inhibition of pancreatic lipase (an enzyme required for the absorption of dietary fat). (12)
You should know: The only study in people with this supplement, showed insufficient results on its use . (13)
6. Garcinia cambogia
It is the fruit of a tree that grows throughout most of Asia, Africa, and the Polynesian Islands. What makes this fruit so important? Its high content of hydroxycitric acid, a derivative of citric acid.
This compound inhibits lipogenesis , food absorption , decreases appetite , and favors glycogen synthesis. That is, it stimulates the uptake of glucose from the bloodstream into the tissues, ready to be used during exercise.
Important: The supposed efficacy of garcinia is contradictory. Some randomized studies had promising results , while others were less so, according to evidence compiled in a meta-analysis published in the American Journal of Clinical Nutrition . (14)
7. Conjugated Linoleic Acid
Linoleic acid is a polyunsaturated fatty acid, which can be found naturally in foods such as eggs, almonds, walnuts, cashews, avocado oil, and tofu. This substance is extracted and sold as a supplement .
To highlight: Studies suggest that it helps to lower body fat by increasing lipolysis and fat oxidation in the muscles , and promotes apoptosis (programmed cell death) of adipocytes, the cells that store fatty acids in our body. What helps to improve the lipid profile of the individual. (fifteen)
Key Findings
- Weight loss supplements are substances sold for the purpose of burning calories , modulating blood glucose levels and making energy available for physical exercise.
- Among these we find caffeine, green tea and green coffee , which promote lipolysis and thermogenesis.
- Others, like glucomannan, are osmotic agents that decrease appetite and make us feel fuller after a meal .
- There are other supplements, such as raspberry ketone , whose clinical effects have not been satisfactorily substantiated.
- The basis of a healthy life consists of a healthy diet , physical exercise and improving your quality of life. Supplements are only a small help and should not be the main focus .
University Professional in the area of Human Resources, Postgraduate in Occupational Health and Hygiene of the Work Environment, 14 years of experience in the area of health. Interested in topics of Psychology, Occupational Health, and General Medicine.