It’s a bit unclear why body composition improves with red light therapy (RLT), but there are some theories, and it likely depends on at least two factors. Firstly, it seems that fat cells simply release fat, which can then be burned, unless you’re sitting on the couch and allow the fat cells to reabsorb it, of course. So, it does require some level of physical activity to fully utilize the effect. However, even if you don’t increase your physical activity, RLT has some effect on body fat. The treatment affects the mitochondria so that their ATP production increases, and that costs energy. This, in turn, provides more energy for various biological processes, which is one of the reasons why red light therapy possesses all the properties attributed to it.
There are many studies on this topic, but one of the studies that showed the most dramatic effect was conducted on 64 overweight women aged 20-40. The study lasted for 20 weeks and included three exercise sessions per week, combining both cardio and strength training, along with red light therapy for the group that received it. The results can be seen in the chart below, but the fact that body fat decreased by an average of 11.26 kg in the group receiving red light therapy is more than twice as much as in the group that did not receive treatment. I am not aware of any method or tool that has such significant effects, at least not while also being healthy. Interestingly, adiponectin, a hormone released by body fat, increases with light therapy. It has a protective effect against metabolic syndrome, high blood pressure, and type 2 diabetes, which was also observed in the study. An added bonus was that muscle mass increased by 0.6 kg in the treated subjects while it decreased by 1.3 kg in the other group. Muscles are metabolically active and will help you maintain body fat at a desirable level. Additionally, they are associated with longevity and health, so it’s a welcome consequence.
Can Red Light Therapy Aid in Weight Loss Without Exercise?
In the study mentioned earlier, overweight women of relatively young age were engaged in both exercise and red light therapy (RLT) treatments. Their substantial excess fat and young age might explain the considerable weight loss, especially in combination with exercise. However, what happens if you try to lose weight without exercise? Many overweight individuals are not accustomed to working out and may not even start due to low self-esteem or reduced mobility. Some may simply be inactive or prioritize exercise poorly. Regardless of the reason, it’s interesting to know if you can achieve weight loss solely through LED light, and this has been investigated.
In one study, 60 overweight adults received LED light therapy with one of three different regimens (1). It was either three times a week for four weeks, twice a week for six weeks, or once a week for twelve weeks. All participants saw reductions in waist circumference and body weight, but the middle group, which reduced an average of 1.1 kg of body fat, stood out. The study does not tell us if perhaps one treatment per day for 20 weeks would be even better, but I suspect both frequency and treatment duration matter. I would like to see a study with daily treatment for a year to draw definitive conclusions about RLT and body weight. This is how the lamps are used for general health, and the weight loss benefits are likely to be reversed if you stop using the lamp, so long-term use is essential.
Contouring
The term implies that it’s not just about weight loss but also about body contours. This might be a healthier goal than just losing weight, as muscle mass should be preserved as much as possible. RLT has the effect of reducing fat while increasing muscle mass. When it comes to studies on “contouring,” the results are somewhat varied, and some seem almost too good to be true. A South Korean study showed that a single treatment could reduce abdominal fat by 18% and double chin fat by 26% in a follow-up 12 weeks after treatment (2). I question whether this is even possible, especially with a single treatment. In my decades as a nutritionist, I have never seen similar results from diet, exercise, or other interventions. Surgery may produce results similar to these, but it should be noted that this is peer-reviewed research published in a reputable journal.
However, if we choose to set aside this study, there are several others showing somewhat more moderate and perhaps more credible results. In one study, participants received one treatment per week for six weeks, with weekly measurements of waist, buttocks, thighs, and abdomen (3). A successful treatment was defined as a reduction of 4.5 inches (11.43 cm), and 72% of participants reached this goal. The average reduction was actually a substantial 5.4 inches (13.72 cm), and over 80% of participants were satisfied with their results. Note that participants did not make any pronounced changes to their lifestyle, attributing the entire measured effect to RLT. However, I would have preferred to see a control group. In another similar study, 86 participants received treatment every other day for two weeks (4). Their results showed a 7.59 cm reduction in waist, hip, and thigh measurements combined. Other studies have also shown similar results (5, 7), and there have even been observed effects on reducing cellulite (6, 8).
- Ivana T. Croghan, Ryan T. Hurt, Darrell R. Schroeder, Shawn C. Fokken, Michael D. Jensen, Matthew M. Clark & Jon O. Ebbert. Low-level laser therapy for weight reduction: a randomized pilot study. Lasers in Medical Science volume 35, pages663–675 (2020).
- Ik Jun Moon 1, Jae Won Choi 1, Chang Jin Jung 1, SeokHwan Kim 2, EunSoo Park 3, Chong Hyun Won 4. Efficacy and safety of a novel combined 1060-nm and 635-nm laser device for non-invasive reduction of abdominal and submental fat. Lasers Med Sci. 2022 Feb;37(1):505-512. doi: 10.1007/s10103-021-03288-z. Epub 2021 Apr 2.
- Carl R Thornfeldt 1, Paul M Thaxton 2, Carl S Hornfeldt 3. A Six-week Low-level Laser Therapy Protocol is Effective for Reducing Waist, Hip, Thigh, and Upper Abdomen Circumference. 2016 Jun;9(6):31-5. Epub 2016 Jun 1. J Clin Aesthet Dermatol.
- Elizabeth McRae 1, Jaime Boris Independent evaluation of low-level laser therapy at 635 nm for non-invasive body contouring of the waist, hips, and thighs. Lasers Surg Med . 2013 Jan;45(1):1-7. doi: 10.1002/lsm.22113.
- Mark S Nestor, Matthew B Zarraga, Hyunhee Park. Effect of 635nm Low-level Laser Therapy on Upper Arm Circumference Reduction: A Double-blind, Randomized, Sham-controlled Trial. J Clin Aesthet Dermatol. 2012 Feb;5(2):42-8.
- Michael H Gold 1, Khalil A Khatri, Kelley Hails, Robert A Weiss, Nathalie Fournier. Reduction in thigh circumference and improvement in the appearance of cellulite with dual-wavelength, low-level laser energy and massage. J Cosmet Laser Ther. 2011 Feb;13(1):13-20. doi: 10.3109/14764172.2011.552608.
- Mary K Caruso-Davis 1, Thomas S Guillot, Vinod K Podichetty, Nazar Mashtalir, Nikhil V Dhurandhar, Olga Dubuisson, Ying Yu, Frank L Greenway. Efficacy of low-level laser therapy for body contouring and spot fat reduction. Obes Surg. 2011 Jun;21(6):722-9. doi: 10.1007/s11695-010-0126-y.
- Elliot Lach 1 Reduction of subcutaneous fat and improvement in cellulite appearance by dual-wavelength, low-level laser energy combined with vacuum and massage. J Cosmet Laser Ther. 2008 Dec;10(4):202-9. doi: 10.1080/14764170802516680.
Author: Fredrik Paulún
