Weight loss supplements register more gross sales than any other category in the natural products industry, just edging out bodybuilding supplements.  Hardly surprising, right?  Almost everyone I know would like to lose a few pounds.

Unfortunately, weight loss supplements are poorly suited to fulfill their stated goal.  In the end it has nothing to do with product quality or specific ingredients that do this-or-that, and everything to do with a concept known as causal density.

Weight loss is multi-factorial, whereas any supplement you take will only have an effect on one or two physiological processes (if that).  You can almost think of your weight as a round number that’s keeping track of everything else you’re doing in your life:  how much sleep you’re getting, how stressed out you are, what you decide to eat three times a day, the quality of your social networks, how often you get laid, the amount of exercise you get, and so on.

In light of all these variables, any pill you take provides you with nothing more than a pathetic little pop-gun in the battle against weight loss.

However, I’ve accepted that nothing I say here is going to stop the vast majority of you from trying a weight loss supplement.  For many of us hope springs eternal, and even if you’re reading some guy on a blog with his own opinion…..what’s the harm in buying a $12 bottle of Garcinia Cambogia?  Doesn’t seem like it could hurt, right?

Well, you’re probably right.  It won’t hurt.  It won’t cause the scale to move at all, but it still won’t do any harm, besides the money you just wasted.

But with all this being said, there’s still a wide spectrum of quality when it comes to weight loss supplements.  They use different ingredients that target different physiological pathways, and have varying levels of research to back their claims.

At the very worst you have some supplements that are little more than caffeine that are unscrupulously laced with low grade pharmaceuticals.  These are shady and illegal, and if you monitor fda.gov closely enough you’ll read a story or two about recalls for these sorts of products.  In the middle you have an ingredient or two that have one paper finding modest weight loss results for a group of people that industry blows up into exaggerated claims.  Raspberry ketones are a good example of this.

At the high end you have ingredients that have well verified health benefits, but they can’t promote sustained weight loss because they only act through one channel, so any benefits they confer will taper off over time.

The Different Types of Weight Loss Supplements

Weight loss supplements can usually be lumped into three different categories:

1. Thermogenic:   A substance that’s thermogenic increases your base metabolic rate and causes you to burn more calories.  Caffeine is the most common and simplest example of this type of compound.
2. Carbohydrate restriction:  Some substances block your body from digesting carbs by inhibiting enzymes that digest it.  These supplements can sometimes be useful for short periods of time (like around the holidays or for bodybuilders doing some ketogenic cycling), but can’t be trusted for prolonged weight loss since they usually act on one enzyme, and the process of weight loss or weight gain involves a deep set of interlocking physiological variables that swallow up one particular reaction over time.
3. Fat utilization:  Your body doesn’t always reliably use the fat that it has.  It’s an enzymatic, equilibrium process that can be artificially held back by hormonal imbalances and bottlenecks that keep your waistline flabby.  Fat utilization supplements aim to remove these checks so your body relies on its internal fat stores more readily.

The Different Ingredients

The total number of ingredients you can find in a fat loss supplement is beyond the scope of this article.  There are about 5,000 total ingredients eligible to be used in dietary supplements, and you could conceivably include any one of them in some quantity.

However, I’ve found that 80% of dietary supplements rely on the following eight ingredients for the bulk of their active ingredients.  Here’s what you ought to know about them:

Green Tea Extract

What It Is:  Green tea extract is the condensed isolate of the green tea leaf (also used to brew the popular beverage), and by almost every measure it’s a nutritional rockstar.  It has a wide variety of beneficial compounds, but the one that’s most prevalent and unique to green tea is a catechin called ECGC.

Catechins are an organic compound that plants make, and some believe they ought to be lumped together with vitamins as essential nutrients.  The health benefits of green tea are broad and well documented, and their association with weight loss came from some clinical studies that linked consumption of green tea with sustained weight maintenance.

How It Works:  It’s thermogenic, meaning it causes your body to burn more calories.

Final Verdict:  Drinking green tea is probably more helpful for maintaining a healthy body weight than shedding lots of pounds.   It does increase your body’s ability to burn calories, but this effect is pretty small, and you’re going to need to drink a lot of tea to do it.  So it does provide tangible benefits, but not enough to make a large impact all by itself.  That said, if I had to buy one supplement advertised as a “weight loss” ingredient, this would be it no questions asked.

Caffeine Anhydrous

What it is:  Caffeine anhydrous is the exact same thing as that more common fatigue-fighting stimulant you know all too well:  caffeine.  Exact.  Same.  Thing.  Sometimes you’ll also see it called trimethyxanthine, which is just its scientific name.  Sometimes supplement labels are more appealing if they have exotic sounding ingredients.

How It Works: Caffeine increases alertness and blood pressure by stimulating certain receptors in your central nervous system.  Like green tea, it mildly increase your metabolism (thermogenic), however caffeine doesn’t offer the wider variety of health benefits that green tea does.

Final Verdict:  Caffeine is a good example of why many weight loss supplements are overpriced.  It takes a very common ingredient that has a legitimate but exaggerated effect on weight loss and mixes it with a few other ingredients to try and bundle it into something that looks much greater than it really is.  If you drink coffee, diet coke, green tea, or any other number of beverages you’ll be getting the same benefits as the caffeine anhydrous contained in weight loss supplements.

Raspberry Ketones

What They Are:  Raspberry ketones are a phenolic compound found in raspberries that were previously used in perfumes because they’re responsible for a raspberry’s fruity aroma.  It was later discovered that they can stimulate certain hormones which trigger the breakdown of fatty acids inside the cell.

How It Works:  Raspberry ketones are a fat utilization supplement, because they purportedly increase the activity of an enzyme called lipase which is used to breakdown fat tissue.  It might also stimulate the release of norepinephrine, which increases energy usage.

Final Verdict:  Despite the advertisements you might see in your local GNC store, when it comes to reputable evidence on weight loss the cupboard is entirely bare with raspberry ketones.  Their purported mechanisms of action are mostly theoretical at this point, and I don’t know of a single study done on humans that demonstrates an ability to aid in weight loss……or anything else.  Stay away from these.  They’re a waste of money.

Green Coffee Beans

What They Are:  Green coffee beans are just like regular coffee beans except they haven’t been roasted yet, which is what makes them green.  Does the un-roasting make them that much more helpful than regular coffee beans?  No, not really.  However, coffee beans do have some properties that make them favorable to weight loss.

How They Work:  Green coffee beans are a carbohydrate restriction type of supplement, because they contain chemicals that block glucose from being absorbed after it’s eaten, and might even affect the expression of certain genes that regulate fat metabolism.

Final Verdict:  Green coffee beans contain some legitimately useful nutrients, and even have a study or two linking them to weight loss, but at the end of the day there’s nothing that separates them nutritionally from regular coffee beans.  Furthermore, the most important nutrient in green coffee beans is chlorogenic acid, which can be found in a wide variety of foods.

Move on here folks, nothing to see.

White Kidney Bean Extract

What It Is:  White kidney bean extract is an isolate from kidney beans that blocks starch digesting enzymes from breaking down long carbohydrates into shorter ones.

How It Works:  It’s a carbohydrate restriction supplement, and specifically works on the enzyme amylase when it’s secreted from the pancreas.  Unlike green coffee beans and raspberry ketones white kidney bean extract has a structure/function claim that’s well verified and has a fairly well established body of research behind it.

Final Verdict:  In the short run I think people can use white kidney bean as a carb blocker.  It’s important to remember that it only blocks starch and not sugar, so you can’t use it with all food groups…..mostly just pasta and bread.  If you’re going to buy a white kidney bean supplement it’s best to use one with the ingredient Phase 2, which is a specific extract that has a higher quality than generic alternatives.

Garcinia Cambogia

What It Is:  It’s a fruit grown in Africa.  Traditionally it’s been used in african curries, but it was recently discovered that it might block fat formation.

How It Works:  It blocks an enzyme called citrate lyase, which is used to create a substance called Acety CoA, which is a precursor for making fat.

Final Verdict:  Despite possibly having certain a certain physiological effect, there’s no reason to believe taking a Garcinia Cambogia pill will help you lose weight.  For one, Acetyl CoA is made in a lot of different ways in your body, so blocking one pathway in your body doesn’t mean your body won’t eventually reset to continue making Acetyl CoA through different channels.  Second, despite its one physiological effect, there’s no evidence that taking Garcinia Cambogia actually helps people who take it to lose weight.  Evidence suggests otherwise.

L-Carnitine

What It Is:  A substance made by your body from the amino acids lysine and methionine.

How It Works:  Carnitine is used to transport fatty acids into your mitochondria so they can be used in a process called beta-oxidation, which is how your body turns fatty acids into energy.

Final Verdict:  L-carnitine is a decent example of there can be a big difference between having a compound do something in your body, and actually taking said compound and experiencing that same effect.  Your body also makes carnitine on its own, so for many people additional l-carnitine taken orally will likely have little effect.

That said, it’s possible that someone suffering from certain micronutrient deficiencies could benefit from taking additional l-carnitine.

Alpha-Lipoic Acid

What It Is:  It’s a naturally occurring antioxidant that allows your body to produce energy from carbohydrates.

How It Works:  It’s a hybrid between a fat utilization and carb restriction supplement.

Final Verdict:  Lipoic acid is no doubt a very important substance in your body, but there’s no reason to believe that it’s beneficial for most people to take it in the form of a vitamin.  When used as a supplement its biggest benefits come from intraveneous injection and not oral dosage.

It’s also important to note that your body makes a version of lipoic acid which isn’t the same as what’s commonly found in products.  The lipoic acid made by your body has a specific geometry which is notated by the letter R, whereas commercially produced lipoic acid has a different geometry which is notated by the letter S.  This might seem like a small difference but they are not the same biochemically, so it’s difficult to say if any of the physiological functions of lipoic acid would hold true by taking synthetically derived S lipoic acid.