Weight loss is a $70+ billion industry in the United States. 
This comes as little surprise, seeing as recent estimates indicate that 71.6% of adults 20 years and older are either overweight or obese. 
Based on these alarming figures, it’s no wonder that fat burner supplements are some of the best-selling products on the market.
While these products are widely used, very few people using them to understand how they work.
Believe it or not, fat burner supplements do not magically “burn off” excess fat from your body.
Put another way; if you are consuming more calories than you burn each day, you will not lose weight, no matter how many fat burner supplements you take.
Remember, these are supplements we’re talking about, not prescription drugs.
That being said, fat burners can help you stick to your diet better and burn more calories during your workout, helping you lose weight more quickly.
Let’s now delve further into how fat burner supplements work.
How Do Fat Burners Work?
How fat burners work are multifactorial, meaning each product works a bit differently. The reason for this is that different ingredients have different effects and can be used to address different pathways that contribute to weight loss.
The foundation or “backbone” upon which most fat burner supplements are built are stimulants, namely caffeine.
Caffeine stimulates the central nervous system, which increases energy, mood, and motivation — three things that can take a severe beating when following a low-calorie diet.
But that’s not all caffeine does; it also helps increase energy expenditure, lipolysis, and fat oxidation. [3,4]
Caffeine can do this by increasing levels of fat-burning catecholamines like adrenaline and noradrenaline.
These chemicals can bind to the beta-receptors on adipocytes (fat cells) and release stored fatty acids into the bloodstream where they can be picked up by carnitine and shuttled into the mitochondria of skeletal muscles to be burned (oxidized) for energy.
Lastly, caffeine (as well as other stimulants) also help suppress appetite, making you feel less hungry and more likely to adhere to your reduced-calorie diet.
Given the multiple ways that caffeine supports weight loss, it’s no wonder why it’s often the first ingredient included when designing a fat burner supplement.
While caffeine is by far the most well-researched ingredient in fat loss formulas, that doesn’t mean there aren’t other ingredients available that can work alongside caffeine to support weight loss.
There are quite a few non-stimulant ingredients that have been found to assist in weight loss.
One of the more notable classes of compounds is thermogenics.
Thermogenesis is the process by which your body burns calories to generate heat.
Prominent thermogenic ingredients typically found in fat burner supplements include:
- Cayenne Pepper (Capsaicin)
- Paradoxine (Grains of Paradise)
- Black Pepper
- Green Tea
In particular, one study compared the effects of three different treatments on calorie burning:
- Green Tea Extract + Caffeine
Researchers discovered that green tea extract + caffeine led to subjects burning ~65 more calories per day than those who just supplemented with caffeine and 80 more calories than individuals consuming the placebo. 
As you can see, the number of extra calories burned from supplements is relatively small in comparison to the total number of calories the body burns in a day. This is why we said at the outset that if your diet isn’t on point, no amount of fat burner supplements will help you lose weight.
Now, if your diet is buttoned up, using a fat burner may help you lose weight a bit quicker and/or experience less difficulty staying on track.
Another avenue by which fat burners help support weight loss is by reducing appetite and increasing satiety.
We already mentioned that caffeine is an ingredient that helps suppress appetite. Other non-stimulant ingredients that help suppress appetite include:
- Cayenne Pepper
Another fat burning supplement that may aid weight loss is through enzymatic inhibition. Essentially, specific ingredients, such as Alluvia® Purple Tea extract, inhibit various enzymes in the body that are involved with the digestion of fats or carbohydrates.
By interfering with the actions of these digestive enzymes, your body may not be able to completely digest some of the fats and carbs you eat, meaning you absorb fewer total calories from a meal.
The final avenue by which fat burner supplements work is a more indirect route.
Above, we said that catecholamines bind to beta-receptors on fat cells, which releases stored fatty acids in the bloodstream and allows them to be used for energy production.
Well, fat cells also have alpha-receptors, and for simplicity’s sake, alpha receptors work counter to beta-receptors, meaning when catecholamines bind to them, it blunts fat burning and up-regulates fat storing.
However, if you have an alpha-adrenoceptor antagonist, such as yohimbine (which can be found in Shredded Steel™), you can help “nudge” more of the catecholamines to bind to beta-receptors.
The reason for this is that yohimbine acting as an alpha-receptor antagonist binds to alpha-adrenergic receptors, which effectually “clogs” the port, thereby forcing adrenaline and noradrenaline to bind to beta receptors. 
When to Take Fat Burners
The fat burner you purchased should clearly state what time of day you should take it as well as how many servings per day you should consider.
Typically, fat burner supplements are consumed either first thing in the morning upon waking or right before your workout.
The reason for taking it immediately upon waking is two-fold:
- It gives you a boost of energy to get moving in the morning (energy can be low when dieting due to low calories).
- It helps suppress appetite, helping you eat less at breakfast and feel less hungry during the day.
If your fat burner contains stimulants, it’s generally recommended to avoid taking them with ~4 hours of bedtime. This is all the more important if you are stimulant sensitive as consuming stimulants too close to bedtime can interfere with sleep.
Should I Take Fat Burners on Non-Workout Days?
Yes, you can take fat burners on non-workout days.
The ingredients in fat burners are there to help increase your energy levels and energy expenditure during the day, both training and non-training days.
Plus, you still eat on non-workout days, and since we know that exercise can help suppress appetite, the fact that it’s a non-workout day may mean that you feel hungrier. As such, using a fat burner on a non-workout day may help reduce the severity of those hunger pangs.
Fat burners are incredibly popular supplements used by individuals seeking to lose weight. They work in several ways, including:
- Increasing Energy
- Boosting Metabolism
- Suppressing Hunger
- Increasing Satiety
- Enhancing Fat Oxidation
Remember that fat burners are not a quick fix or magic pill for weight loss.
They can help to burn more fat and lose weight faster when combined with proper diet and exercise, but they cannot replace them.
- LaRosa, John. “Top 9 Things to Know About the Weight Loss Industry.” Market Research Blog, blog.marketresearch.com/u.s.-weight-loss-industry-grows-to-72-billion
- Table 53 . Selected health conditions and risk factors , by age : United States , selected years 1988 – 1994 Total , crude Table 53 . Selected health conditions and risk factors , by age : United States , selected years 1988 – 1994 through 2015 – 2016 Trend Tables. (2017), 2016–2017.
- Ryu, S., Choi, S. K., Joung, S. S., Suh, H., Cha, Y. S., Lee, S., & Lim, K. (2001). Caffeine as a lipolytic food component increases endurance performance in rats and athletes. Journal of Nutritional Science and Vitaminology, 47(2), 139–146. https://doi.org/10.3177/jnsv.47.139
- Tabrizi, R., Saneei, P., Lankarani, K. B., Akbari, M., Kolahdooz, F., Esmaillzadeh, A., Asemi, Z. (2019). The effects of caffeine intake on weight loss: a systematic review and dos-response meta-analysis of randomized controlled trials. Critical Reviews in Food Science and Nutrition, 59(16), 2688–2696. https://doi.org/10.1080/10408398.2018.1507996
- Shixian, Q., VanCrey, B., Shi, J., Kakuda, Y., & Jiang, Y. (2006). Green tea extract thermogenesis-induced weight loss by epigallocatechin gallate inhibition of catechol-O-methyltransferase. Journal of Medicinal Food, 9(4), 451–458. https://doi.org/10.1089/jmf.2006.9.451
- Dulloo, A. G., Duret, C., Rohrer, D., Girardier, L., Mensi, N., Fathi, M., Vandermander, J. (1999). Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. The American Journal of Clinical Nutrition, 70(6), 1040–1045. https://doi.org/10.1093/ajcn/70.6.1040
- Lafontan, M., Berlan, M., Galitzky, J., & Montastruc, J. L. (1992). Alpha-2 adrenoceptors in lipolysis: alpha 2 antagonists and lipid-mobilizing strategies. The American Journal of Clinical Nutrition, 55(1 Suppl), 219S-227S. https://doi.org/10.1093/ajcn/55.1.219s