How Red Light Therapy Burns Body Fat: Resting Metabolic Rate Boost In New Study!

Another week, another newsletter! Today we're covering a very exciting new study showing an increase in metabolic rate - so the calories that you burn, with red light therapy. Many people have been asking in our FB group how fat loss can occur with light therapy.

And, people implicitly assume that, somehow, red light therapy doesn't boost fat loss, or cannot influence it. Nothing could be further from the truth.

Also, at the bottom of this newsletter, we've added the latest articles...

October 2025 Resting Metabolic Rate Study

Recently I've published my article/video on red light therapy for fat loss. Check that article here:

Many people ask how it is possible in the first place that red light therapy burns body fat. Often, these people find themselves in the kcal in vs. kcal out model of weight loss and have a hard time explaining how red light therapy works as it doesn't change your movement or wat you put in your mouth.

So there's a very exciting October 2025 study that came out on resting metabolic rate and light therapy. "Resting metabolic rate" are the calories you burn 24/7, in rest, even without doing anything. Resting metabolic rate is responsible for basic organ function, for instance, and you wouldn't be alive without it.

Here's the study I'm talking about:

Now, in this study, one single 12-minute session with a red light therapy bed, led to an increase in resting metabolic rate in obese women, but not women with normal bodyweight:

As you can see, there's an increase in the PBM group on the right, in terms of calories burned. And in good medical lingo, the difference between the sham treatment (participants laying in a bed that doesn't work) and the intervention treatment (a work light therapy bed) is statistically significant.

Here's what the researchers write about this dynamic:

"The present study provides preliminary evidence that acute photobiomodulation can transiently augment resting energy metabolism in women with obesity, as reflected by a ~9% increase in resting energy expenditure following a single 12-min exposure to red and near-infrared light. Notably, this effect occurred without any change in the respiratory exchange ratio, suggesting that substrate oxidation remained stable. These findings should be interpreted as short-term physiological responses rather than definitive evidence of metabolic enhancement. The study was designed as an acute, controlled experiment to explore immediate effects under standardized conditions, serving as a necessary preliminary step toward future longitudinal trials."

So yes, it's a very important finding as now we have a mechanism through which people may increase their fat loss with red light therapy. Again, this mechanism question was one of the most frequent counterarguments against red light therapy causing fat loss when I published my article/video on the topic. People generally couldn't believe that you can lose inches around the midsection with light therapy.

One caveat with the study I'm discussing today is that we still don't know how exactly the calorie burn increase happens. Yes, we know that red light therapy influences mitochondrial function, which should, in theory, increase fat burning or energy consumption as well.

The increase in kcal burned is also not because of heating, as researchers write:

"The increase in back and front skin temperatures following [light therapy] suggests that thermogenic effects might contribute to the higher energy expenditure observed. However, our additional correlational analysis showed no significant association between changes in temperature and changes in [Resting Energy Expenditure], supporting the independence of the metabolic response from surface heating."

Keep in mind that "Resting Energy Expenditure" (REE) or "Basal Metabolic Rate" (BMR) is the biggest calories expenditure people have during their day. A 9% increase is thus potentially a huge game-changer, especially if you can achieve that with only a 12-minute red light therapy session.

And, yes, the results only occurred in obese women, not those with normal bodyweight. Also, a lot more research is necessary to fully understand the dynamics here, so that we can apply this principle to other situations.

What device was used? This is a red light therapy bed. I do question the numbers given in this description below, however, as I think the power output mentioned for the device is far excessive:

"The device (LED PRO, CTN, Helsinki, Finland) is shaped like a bed (dimensions: 192 × 85 × 95 cm) and equipped with 28,512 LEDs emitting red light (λ = 633–660 nm) and near-infrared light (NIR, 850–940 nm) in continuous mode, without interruptions. This configuration produces an irradiance of 129 mW/cm² and a fluence of 92.9 J/cm² at a distance of 5 cm from the supine contact surface , and 5–10 cm from the anterior body surface , depending on thoracic–waist circumference."

Which leads to the following study setup:

The 129 mW/cm2 would be about 5X of what you'd be getting from the industry standard, the NovoTHOR. Check more on that here:

Also check my article about fat loss HERE, once more!

Check Out Some Of Our Other Content:

Below you'll find some of our best content that you shouldn't miss:

Red Light Therapy For Hair Regrowth: HUGE 6-Month Test! - Yes, a huge experiment by Alex, combining medicine for hair regrowth with a helmet, as is used in many of the studies. Here's the outcome.
Pulse Light vs Continuous: What Actually Matters in Red Light Therapy - Should you use pulsed light? And who should use pulsed light, and in which circumstances? Alex explores the ins and outs of the science!
Red Light Therapy April News: New Devices, Science & Industry Shifts - Once more, the latest red light therapy news: new devices, new science, Q&A from our Facebook group, current and upcoming content we've published, and much more!
Red Light Therapy For Sleep: 10 Groundbreaking Studies - Bart considers all of the available red light therapy & sleep studies here, and teaches you how to apply these insights into sleep quality improvement. These studies show groundbreaking results for deep sleep, melatonin levels, recovery, and other areas.

Light Therapy Advanced Science Course - Contains Content On Exercise Performance Too:

Join Bart's 100% free advanced science light therapy course above, where he takes deep dives into many different topics, such as mechanisms, neurology (Alzheimer's, Parkinson's, etc), exercise recovery, skin beauty & rejuvenation, and much more.

Some of the topics are only published in that course, such as UV light risks and benefits, addiction, anxiety, depression, and more. So join HERE!