Testosterone is known to promote fat loss. The more testosterone you have the leaner you will be.

People take this to the extreme and think that high testosterone will make you shredded. Absolutely peeled. No diet or exercise is required. Just sky-high testosterone.

I just want to provide some context here and what you can expect.

Testosterone and fat loss

Testosterone helps with fat loss, since it:

• Improves insulin sensitivity
• Inhibits adipogenesis (formation of new fat cells) and fat cell hypertrophy (very large fat cells cause inflammation and contribute to insulin resistance) (R).
• Promotes the formation of muscle cells, instead of fat cells from mesenchymal pluripotent cells.
• Inhibits triglyceride uptake and lipoprotein lipase (which inhibits excess lipolysis (R)) activity resulting in rapid turnover of triglycerides in the subcutaneous abdominal adipose tissue.
• Mobilizes lipids from the visceral fat depot.
• Increases motivation, enhances mood, and promotes a more active lifestyle, thus preparing the body for physical activity and increased energy expenditure, thus contributing to further weight loss.
• Suppresses orexin A, which stimulates appetite (R).
• Improves mitochondrial function, thus enhancing ATP production and energy expenditure.

Long-term testosterone therapy in men with testosterone deficiency produces significant and sustained weight loss, marked reduction in waist circumference and BMI and improvement in body composition. However, it takes a long time. Years to be precise. Maybe even up to a decade (R).

Testosterone and BMI association

People with higher testosterone are more likely to have a lower BMI, or is because people with a normal BMI are more likely to have higher testosterone. I think it’s both. A lower BMI is more conducive to having higher testosterone.

Obesity lowers testosterone via multiple mechanisms, such as:

• Enhances inflammation
• Leptin resistance
• Insulin resistance
• Sleep disruption
• Increased heat in the testes
• Elevated estrogen
• etc.

Even though people with a normal BMI can have low testosterone, the risk of hypogonadism increase significantly as BMI goes up. The prevalence of hypogonadism in adolescent and young adult males with obesity varies anywhere from 30–60% based on different criteria used for the diagnosis and severity of obesity.

A 2013 study found the prevalence of hypogonadism in 161 adult males with a median age of 45 years to be around 32% and also showed that 75% of subjects with severe obesity (BMI > 40 kg/m²) had hypogonadism (R).

Losing fat can help to increase testosterone, but by itself, it’s usually not enough to get rid of hypogonadal symptoms. You need to optimize your diet and lifestyle as well.

Study 1: 11 year study

All groups upon starting had testosterone under 300ng/dl. Even the normal weight group was hypogonadal. So clearly, just being hypogonadal doesn’t mean you’ll pack on weight or that increasing T will make you shredded.

The average BMI for each group was 24, 27.5, and 36.4.

With injections, T when up by 257, 245 and 228ng/dl in the normal, overweight and obese groups respectively. So they had around 500ng/dl testosterone (with injection) that resulted in quite decent fat loss over a decade. Would they have gotten better fat loss if they had 1000ng/dl testosterone? Likely.

In normal men, TRT dropped weight by 3.4 ± 1.2 kg over 11 years (less than 1 in the first year) and reduced BMI by about 1 point over the same time frame. Super wow body recomp right?

In overweight men, TRT dropped weight and BMI by 8.5 ± 0.4 kg and 3 points respectively. This would take them from 27.5 to about 24.5 after 11 years. Still not shredded.

In obese men, TRT dropped weight and BMI by 23.2 ± 0.3 kg and 8 points respectively. This would take them from 36.4 to about 27.4 after 11 years. Still overweight.

A BMI over 25 and 30 is considered overweight and obese respectively.

Study 2: 5 year study

BMI declined from 31.7 ± 4.4 m kg^-2 to 29.4 ± 3.4 m kg^-2 over 5 years by keeping T at 500-600ng/dl.

Progress, but disappointing.

Study 3: 5 year study

Another 5 year study while keeping T around 500-600ng/dl. BMI (m/kg(2) ) declined from 33.9 ± 5.51 m/kg(2) to 29.13 ± 3.09 m/kg(2) (R).

Study 4: high dose Testosterone for 20 weeks

This study was good because they did different doses of testosterone, namely 50mg, 125mg, 300mg and 600mg per week. They gave 1 group dutasteride + T and the other group just T.

Among participants who received placebo plus testosterone enanthate, the mean testosterone level went from:

• 697ng/dl to 385 ng/dL on 50 mg/wk
• 701 to 822 ng/dL on 125 mg/wk
• 667 to 1702 ng/dL on 300 mg/wk
• 776 to 3578 ng/dL on 600 mg/wk (R).

5kg of fat loss after 20 weeks at test level at 1700ng/dl. 5kg after almost half a year. Interestingly, the 600mg T group lost less fat than the 300mg T group. The black dots are guys who took dutasteride + T. This shows that DHT, at least in high amounts, helps with fat loss.

5kg of fat loss in 20 weeks is good, but if you do fat loss and lose 0.5kg per week, you’ll lose 10kg in 20 weeks. Cutting calories is still better for fat loss.

A very similar study (at the same varying doses and for the same duration) only reported a 1.8kg decreased fat mass by 20 weeks on the 300-600mg doses (R).

Very high T, much higher than what TRT will give you, will only give you 1.8-5kg of fat loss in 20 weeks unless your diet is also improved.

Study 5: 8 year study

8 year study maintaining testosterone around 500ng/dl.

No one is getting shredded on just TRT.

However, other benefits include improved cholesterol, fasting blood sugar, trigs, HDL, LDL, hsCRP, blood pressure and liver enzymes (R).

Study 6: 10 year study

10 year study maintained testosterone between 500-600ng/dl.

Even though BMI plateaued after about 6 years, waist circumference continued to go down, which is generally a sign that fat mass is still going down and muscle mass likely going up.

Why does testosterone work?

The 2 biggest reasons are because it improves your mood and energy as well as appetite.

Thus you’re more likely to be active, pursue goals and eat less (due to enhanced appetite and improved insulin sensitivity). Plus, if you’re feeling better and more motivated, you’re more likely to eat a healthier diet.

What would have been better is if they could keep their T around 1000ng/dl and fat loss would likely have been even better.

However, is it going to make you look shredded?

No. Eating right (and often less) and moving more is the best way to stay lean. Some people argue that they can eat a lot while not doing exercise. But that’s because they are restless people in general. I’m not restless so if I just eat to appetite (most of the time bored eating, or just snacking for the sake of snacking), I gradually gain weight month after month. About 0.5-1kg per month. After 1-2 years I suddenly realize…I’m fat.

Summary: Testosterone helps with fat loss and definitely improves body composition. However, I’ve seen many guys on high doses of testosterone combined with tren and you won’t even be guessing that they lift at all.

Don’t take eating right (and in the right amounts) and lifting for granted. There is no easy way out. If you want to look good, eat good.

Related articles:

• Prolactin and weight gain
• Serotonin and weight gains
• How to increase dopamine (dopamine improves your energy and satiety)
• How to increase testosterone
• DHT and fat loss

If you need help getting your hormones and body comp back on track, reach out below or book a free call with me.