What happens to testosterone and thyroid levels during and after a diet? How long does it take for them to recover? Answers here.
In 1944, Ancel Keys studied starvation by placing volunteers on a severe calorie restriction for 24 weeks. They ate mostly potatoes, turnips, and bread.
The volunteers lost roughly 25 percent of their body weight and experienced slower metabolism, muscle loss, weakness, and even depression. And recovery took far longer than expected.
While that study is now considered ethically questionable, similar effects can be studied today by observing physique competitors who intentionally undergo extreme dieting to achieve contest-level leanness. What can we learn?
The newer study
This study focused on weight-lifting females: 27 amateur competitors preparing for shows. Seventeen were bikini competitors, nine were figure competitors, and one was in the fitness division.
The researchers wanted to find out what happens health-wise during the 4-month pre-competition period, along with how well they recover from the strict dieting and increased training. After dozens of lab tests, the participants did what they always do: reduced calories, lowered carbs, kept protein high, lifted weights, and increased cardio or HIIT.
The results
Most saw a 35 to 50 percent decrease in fat mass – they got ripped. Muscle size was either maintained or only slightly decreased. Weight training plus a higher protein diet allowed them to keep all or most of their muscle, the researchers concluded.
That's all good, but it wrecked their hormonal systems. "Leptin, T3, testosterone, and estradiol decreased," researchers noted.
After their shows, the subjects kept lifting, decreased their cardio, and brought their calories and carbs back up to normal. In 3-4 months, hormone concentrations returned to baseline. Well, most of them. "T3 and testosterone were still slightly decreased compared to pre-diet," researchers noted.
The researchers looked at these results positively since muscle was mostly maintained and hormone levels returned to normal, or close to it, in the four months after the show. But four months is a long time to be hormonally hamstrung, especially regarding thyroid and testosterone. And many competitors do more than one show in a season.
What we can learn
With a high protein intake and weight training, muscle loss can be minimized or avoided, even during an extreme diet. The women in this study consumed 3 grams of protein per kilogram of body weight. That means a 140-pound woman consumed around 190 grams of protein daily. Most of the women in the study used protein powder (Buy at Amazon) to hit those numbers.
The damage done by a competition diet can be repaired, but it takes 3-4 months, maybe longer. Female competitors (and anyone going on a super-strict diet) should be aware of the hormonal changes, especially thyroid and testosterone.
How to minimize the risks
Certain supplements can help both men and women on a strict fat-loss diet, like a specific form of forskolin.
Forskolin supports thyroid health by stimulating the production of thyroid hormones, particularly T4. Remember, thyroid hormones play a crucial role in regulating metabolism. Forskolin increases TSH or thyroid stimulating hormone, which leads to an increase in metabolic rate. Taking forskolin during and after a strict diet should prevent the associated thyroid problems.
Along with thyroid support, forskolin increases protein kinase production, which leads to increased levels of hormone-sensitive lipases (HSL), which helps break down triglycerides. Basically, it increases the breakdown of fat cells and releases stored fat from adipose tissue.
If you use the more bioavailable form, forskolin also increases the activation of brown adipose tissue (which increases fat burning), boosts protein synthesis, and increases testosterone levels in men.
The bioavailable form of forskolin is called forskolin 1,9 carbonate. It was invented by Biotest and is sold as Carbolin 19 High-Performance Forskolin (Buy at Amazon). It's better absorbed and the effects last longer than standard forskolin.
Taking two softgels once per day during and after a diet should minimize or prevent the problems the study's subjects experienced, further promote muscle preservation, and help prevent fat regain after a hard diet.
Reference
- Hulmi JJ et al. "The Effects of Intensive Weight Reduction on Body Composition and Serum Hormones in Female Fitness Competitors." Front Physiol. 2017 Jan 10;7:689. PMC: PMC5222856.
