In my 1992 book on Wilson’s Temperature Syndrome, I shared my clinical findings linking low body temperature and easy weight gain. Now these same findings are being documented in the medical literature. A new study has found that obese people (BMI >30) have lower body temperature during the day than normal weight people. The obese people had an average body temperature that was .63 degrees F cooler than normal weight people. The researchers calculated that this lower body temperature—which reflects a lower metabolic rate—would result in a body fat accumulation of approximately 160 grams per month, or four to five pounds a year, enough for the creeping weight gain many people experience.

Even though it was small, this study is impressive because it was so rigorously controlled. Participants had rectal temperature monitoring every two minutes, starting three hours after they woke up. They stayed in a constant, temperature-neutral environment, had fixed caloric intake and had minimal physical activity during the time they were in the study. That meant that any variables that might affect core body temperature were controlled.

The study excluded people with known endocrine/thyroid disorders, and it did not examine why obese people had lower body temperatures. However, I believe it is probable that the obese group did include people with undiagnosed Wilson’s Temperature Syndrome. These people may have trouble converting T4, the inactive form of thyroid hormone, to T3, the active form.

Research shows that T3 is directly responsible for maintaining body temperature. It does this, in part, by generating heat in the body’s brown fat, a unique form of fat whose only purpose is to generate heat. Most T4-to-T3 conversion occurs directly in the brown fat, so people who don’t convert T4 to T3 efficiently would have low body temperature, even if their blood levels of T4 and TSH are normal.

I think it is important for people who are overweight to check their body temperature. (For directions on how to do this correctly, see “How are body temperatures measured” on our website.) If your body temperature is consistently low—below 98.5 F., or 36.94 C, but typically lower than 97.8 F, or 36.56 C.— there’s a good chance that you have slow metabolism. It may mean that you are not converting enough T4 to T3.

Proper body temperature is important not just to feel warm. Body temperature affects every process in your body, including the ability to burn calories. In fact, the researchers in this study say as much: “This finding supports the growing scientific interest for body core temperature as a new therapeutic target for the treatment of obesity.”

I’ve found that normal body temperature can be restored in most people with a course of T3 therapy. This is the case even if they have normal blood levels of TSH or have been taking T4 (Synthroid.) As body temperature normalizes, people see improved mood and more energy. They also seem to have an easier time losing weight. It’s not a matter of just taking thyroid medicine. It’s a matter of normalizing the body temperature. I’ve had patients who have lost over 100 pounds once their temperatures were normalized, even when they were not able to lose previously. One patient of mine, once her temperature was normalized, lost over 30 pounds in one month without changing her diet or exercise. (Her other symptoms of low thyroid function resolved as well).

My mission is to teach as many doctors as possible about low temperature protocols, in order to help as many people as possible. If you’re someone who might benefit from this therapy, please share this article with your doctor, or have him/her read my book. Any doctor can call us at 800.420.5801 to get more information about how to use T3, along with nutritional and herbs to support thyroid health, and to discuss your individual case. You can also use our website to find the health care practitioner closest to you who is trained in T3 treatment.

Bianco, AC & McAnich, EA. The role of thyroid hormone and brown adipose tissue in energy homoeostasis. The Lancet Diabetes and Endocrinology v. 1 n. 3 (Nov. 2013) pp. 250-8.

Grimaldi D, Provini F, Pierangeli G, et al. Evidence of a diurnal thermogenic handicap in obesity. Chronobiol Int. 2015 Mar;32(2):299-302.

Major GC, Doucet E, Trayhurn P, et. al. Clinical significance of adaptive thermogenesis. Int J Obes (Lond). 2007 Feb;31(2):204-12.

Whittle AJ, López M, Vidal-Puig A. Using brown adipose tissue to treat obesity – the central issue. Trends Mol Med. 2011 Aug;17(8):40