Fat loss pills. Protein powders. Creatine.
These are probably all supplements you’ve heard of or are even familiar with if you’ve ever stepped foot in a gym.
Supplement manufacturers are quick to tout the amazing benefits of these products to help you burn fat, build “lean muscle”, and get six pack abs.
And apparently they’re pretty convincing … because the global dietary supplement industry made $132.8 billion in 2016 and that number is expected to increase to $220.3 billion by 2022.
But do these supplements actually make a difference when it comes to body composition?
In this article, we’ll break down the real science behind the most popular dietary supplements and show you which ones appear to work, which ones don’t, and some you may even want to avoid for safety reasons.
Let’s start with what works.
There’s no shortage of dietary supplements on the market these days marketed toward people trying to improve lean body mass.
However, there are a few that actually directly support body composition improvement (i.e., they’re backed by peer-reviewed, placebo-controlled clinicals trials).
We’ll break down the evidence supporting each.
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Protein powders are one of the most common nutritional/dietary supplements. You can now buy protein powders from a variety of sources: milk-based (whey and casein), egg-based, or plant-based (rice, hemp, pea, pumpkin seed, and soy, to name a few).
Whey protein has been studied more than any other protein powder. A quick search of “whey protein powder” on PubMed brings up close to 400 studies to date.
While you can certainly find studies like this one that showed no link between whey protein and body composition, the overall body of evidence seems to suggest whey does, in fact, have some type of impact.
A meta analysis (a review of a group of studies) published in the Journal of the American College of Nutrition looked at 14 clinical studies including a total of 626 adults and concluded that whey protein powder has favorable effects on body composition (and is even more effective when combined with resistance training).
Rice protein is a plant-based protein powder used by vegans, vegetarians, and people who can’t tolerate dairy products like whey. In one study published in the journal Nutrition, researchers found that rice protein had similar effects on body composition as whey. There was no difference between the group of subjects that took rice protein and the one that took whey protein; both experienced positive body composition changes.
Soy protein is another popular plant-based protein powder that gets a bad rap because it contains isoflavones, phytoestrogens that share similarities with estrogen (and because it’s often extracted using hexane, a petroleum-based solvent).
However, according to several studies, soy protein may be beneficial to body composition for older women in particular.
One study showed that a daily supplement of soy protein prevented increases in subcutaneous and total abdominal fat in older women. Another showed soy protein had a mild effect on body composition in elderly women.
One caveat: whey has been shown to be more effective than soy for improving lean body mass when combined with resistance training. So if lean body mass is your goal, you may want to consider other protein sources than soy if you’re using a protein powder.
The Bottom Line About Protein
In a study published in the Journal of the International Society of Sports Nutrition, researchers compared muscle development in three groups of athletes on the same exercise routine but with different protein intake levels.
One group was given less than the daily recommended amount (RDA)--1.4g/kg of body weight, the second group received the current RDA of 1.8g/kg of body weight, and the third group had more than the RDA (2.0g/kg of body weight).
The researchers found no improvement in strength or body composition in the group that consumed the most protein. They concluded that 1.8 grams per kilogram of body weight was sufficient to see favorable changes in body composition in athletes.
For non-athletes and particularly older adults, eating around 0.8 g/kg per day has been shown to help preserve lean body mass.
Long story short, most people don’t need to guzzle down protein shakes like bodybuilders and gym rats to see changes in body composition.
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Creatine is a popular supplement among bodybuilders and athletes because of its apparently positive effects on muscular strength.
One small study showed that creatine when combined with other supplements (glucose/taurine/electrolytes) promoted gains in fat/bone-free mass, lifting volume, and sprint performance during intense resistance/agility training.
Getting stronger often leads to improvements in lean body mass, but it’s not totally clear if the creatine itself is responsible for this. If you use creatine along with other supplements and resistance training exercises, you’ll see positive changes in your body composition regardless.
There’s some compelling research about the effects of beta-alanine on body composition.
Supplementation with beta-alanine appears to stimulate lean body mass growth in athletes. Also, beta-alanine may enhance high intensity interval training (HIIT) sessions, which can lead to improvements in endurance performance and lean body mass.
A group of researchers published a paper in the International Society of Sports Nutrition (ISSN) reviewing several published studies on beta-alanine supplementation and concluded that four weeks of beta-alanine supplementation (4–6 g/day) may improve skeletal muscle mass and exercise performance (although the effects on strength and endurance exercise beyond 25 minutes needs further study, according to the researchers).
It seems like beta-alanine is a good choice to add into your supplement-taking routine to help with endurance, which in turn can help with increasing muscle mass.
HMB, or beta-hydroxy beta-methylbutyrate, is a metabolite of the essential amino acid leucine that has been used as a dietary supplement in the bodybuilding community for years.
There are mixed opinions about how HMB impacts body composition.
One study published in the Journal of Strength and Conditioning Research found that HMB led to “advantageous changes” in body composition among athletes. However, another small study among athletes found that HMB helped athletes substantially increase their lower body strength … but the effects on body composition were insignificant.
Another team of researchers concluded that HMB may help preserve muscle mass in older adults.
Long story short, it appears that HMB is effective for helping you preserve lean body mass. Whether it helps with fat loss or building lean body mass, it still needs to be studied more.
The evidence around fat loss dietary supplements is a little dicier. In general, there’s a lack of peer-reviewed, placebo-controlled clinical trials for most supplements on the market. There are a few, however, that show promise if weight loss is your goal.
Let’s take a look at a few of them.
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MCTs, or “medium chain triglycerides,” are a form of saturated fatty acid found in coconuts with some pretty intriguing body composition effects.
For starters, MCTs provide about 10% fewer calories than LCTs (long chain triglycerides). On top of that, MCTs are not stored in fat deposits in the body as much as LCTs and have been shown to enhance thermogenesis (fat burning) in animal studies.
One small study published in the American Journal of Clinical Nutrition showed that MCT oil leads to a greater rate of weight and fat mass loss compared to olive oil. So even just small changes to your diet like cooking with coconut oil instead of olive oil can promote some weight loss.
And perhaps most interestingly was a small study published in the journal Lipids. Forty obese women were split into two groups. One group consumed 10 ml of soybean oil and the other 10 ml of coconut oil at each meal, three times per day for 12 weeks. Both groups followed a low-calorie diet and walked 50 minutes each day, as well.
Both groups lost the same amount of weight; however, the coconut oil group had a statistically significant decrease in waist circumference (plus a 35% decrease in C-reactive protein (CRP), a marker of inflammation). While this study didn’t look at MCT oil powder, specifically, it did show a correlation between medium chain triglycerides and reduced fat around the abdominal region, a goal most people aspire for.
While more research is needed to show that MCT powder caused the changes in body composition, these studies are definitely worth noting. And changing some of the fats in your diet could help you cut a few calories and hit your fat loss goals a little quicker.
Next, let’s look at a few supplements you may have heard improve body composition … but the science says otherwise.
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While green tea certainly has some beneficial effects, its impact on body composition has been largely overstated.
A group of researchers conducted a meta-analysis on the effects of green tea and concluded the following:
Green tea or green tea extracts intake or its extracts exerts no statistically significant effect on the weight of overweight or obese adults. There is a small effect on the decrease in the percentage of fat mass, but it is not clinically relevant.
So if you love all things green tea, they might not help you lose weight but it sure tastes good!
Caffeine pills are the newest up and coming trend in easy hacks for weight loss. But how effective is caffeine in weight loss? Caffeine has been shown in several clinical studies to have a “possible modest effect on body weight or decreased weight gain over time.”
As any daily coffee drinker knows though, there are some side effects associated with caffeine (or lack thereof), including nervousness, jitteriness, and in extreme cases, vomiting and tachycardia.
Caffeine in pill form can have negative side effects though. A group of researchers published a paper in the International Journal of Sport Nutrition and Exercise Metabolism saying that “weight-loss supplements containing metabolic stimulants (e.g., caffeine, ephedra, synephrine) are most likely to produce adverse side effects and should be avoided.”
So all in all, caffeine can act as a stimulant and increase caloric expenditure slightly, but you probably don't want to up your caffeine intake expecting it to cause notable fat loss.
Glutamine is another popular supplement among gym-goers because of its purported muscle-building benefits.
However, when researchers examined the effect of glutamine supplementation in 18-24-year-olds, they concluded that glutamine supplementation during resistance training has “no significant effect on muscle performance, body composition or muscle protein degradation in young healthy adults.”
While glutamine supplementation may help you recover faster and decrease soreness after a tough workout, it’s not going to have any impact on your body composition directly.
The Journal of Biomedical Science calls taurine a “wonder molecule.”
But its direct effects on body composition aren’t so wondrous.
One study showed no significant correlation between dietary taurine intake and body composition improvements among obese adults.
Another found that in adults with heart problems, 1500 mg of taurine daily was associated with physical improvements and increased exercise capacity but not body composition.
Because the effects of taurine aren’t completely understood, take taurine sparingly to possibly help increase your exercise capacity. With a higher exercise capacity, you’re making greater strides to start burning fat the more you work out!
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Calcium is one of the most important minerals when it comes to bone health. It can help improve your bone mineral density (though the effect is small), and is responsible for many other functions within your body.
For body composition though, it has zero impact.
Branched Chain Amino Acids, or BCAAs, refers to three amino acids: leucine, isoleucine, and valine, that are integral to protein synthesis (or muscle repair/growth) and energy production.
BCAA supplement companies often cite research that demonstrates the anabolic effects of BCAA supplementation to sell their products.
However, all the research really tells us is that increasing BCAA levels (and leucine in particular) before and after exercise may help build more muscle.
There’s simply no evidence that taking a BCAA supplement to improve your body composition has any effect.
There are a handful of nutritional supplements that show promise when it comes to improving your body composition. MCT powder/oil may help promote fat loss over the long term, but only if it is strategically placed to create that caloric deficit. Thermogenics (caffeine and green tea) and taurine are probably not going to promote noticeable fat loss.
Despite supplement manufacturers’ clever marketing campaigns, the bottom line is most of the products they’re pushing just don’t work.
Dietary supplements can do just what their name implies: provide supplemental nutrition. That doesn’t mean they can replace a healthy diet and good old fashioned exercise, and taking a bunch of pills won’t make you suddenly stronger than the next guy.
When it comes to improving your body composition, start with the basics. Get your body composition tested to see your starting point and tailor your diet and exercise accordingly. Then if you think you need a supplement to gain those last few pounds of muscle, or lose those last few pounds of fat, consider the ones we mention above that are backed by solid data.
Scott Christ is a health and wellness entrepreneur, writer, and website strategy consultant. He's also the creator of the world's healthiest plant-based protein powder.