For thousands of women with hypothyroidism, especially between 30–45 years, this is the MOST confusing part of their health journey.
“I barely eat 1–2 meals a day… still I’m gaining weight. How is it possible?”
The answer is simple:
📌 Your biology has changed
📌 Your hormones have slowed down
📌 Your metabolism is not the same as it used to be

This newsletter explains the REAL science behind thyroid-related weight gain in women.

1️⃣ Hypothyroidism Can Slow Metabolism by Up to 40%

Your thyroid controls metabolism — the rate at which your body burns calories.

When thyroid hormones drop:

Your body burns fewer calories at rest
- Fat storage increases
- Digestion slows
- Energy production decreases

Even if you reduce your food intake, your metabolism adjusts downward and burns even less.

✔ This is why women say:

“I’m eating so little. Why don’t I lose weight?”

Because your body is burning far fewer calories than before.

What research says:
📌 Studies show that people with hypothyroidism experience a 30–40% reduction in resting metabolic rate (RMR).

2️⃣ Reverse T3 Puts the Body into ‘Survival Mode’

When you:

- Skip meals
- Eat too few calories
- Live under stress
- Have uncontrolled hypothyroid

Your body increases Reverse T3 (RT3) — a hormone that blocks active thyroid function.

RT3 tells your body:

“Stop burning fat. Save energy. Store everything.”

This is why women with thyroid find weight loss almost impossible despite strict dieting.

Research shows:
📌 High RT3 is linked to impaired metabolism, fat storage, and chronic fatigue.

3️⃣ Leptin Resistance: Your Brain Stops Recognising Stored Fat

Leptin is the “fat-regulation hormone.”
It tells the brain:
“You have enough fat. You don’t need more.”

But in hypothyroid women, leptin resistance is common.
Your brain never gets the message.

Result:
- Increased hunger
- Strong cravings
-Slowed metabolism
- More fat storage

Even if you’re NOT eating much, your body behaves as if:

“We are starving. Hold onto every calorie.”

Research evidence:
📌 Women with hypothyroidism show higher risk of leptin resistance, leading to weight gain independent of calories.

4️⃣ Insulin Resistance Makes Belly Fat Accumulate Faster

Hypothyroidism naturally increases insulin resistance.

High insulin = Your body stores fat easily, especially on the belly, waist, and hips.

This means:
Even healthy foods like roti, dal, rice, fruits can spike blood sugar → which triggers insulin → which stores fat.

And because your metabolism is slow…
The fat stays.

Studies show:
📌 Patients with hypothyroidism commonly develop insulin resistance, making weight loss extremely difficult.

5️⃣ Chronic Inflammation & Water Retention Increase Scale Weight

Hypothyroidism triggers:

- Tissue swelling
- Water retention
- Puffiness
- Bloating
- Slow digestion

This means:
The scale may show 2–5 extra kilos that are not even fat — just water + inflammation.

This is why many women feel:

“I look swollen or puffy even without overeating.”
Research:
📌 Thyroid hormone deficiency leads to increased inflammatory markers and fluid retention.

6️⃣ Stress, Poor Sleep & Hormones Work AGAINST You

Women in the 30–45 age bracket often juggle:
- Work
- Family
- Kids
- Household responsibilities

Chronic stress raises cortisol, the hormone that stores belly fat.

Poor sleep lowers thyroid hormone conversion (T4 → T3).
Low T3 = Ultra-slow metabolism.

⭐ THE TRUTH MOST WOMEN NEED TO HEAR

👉 You are NOT gaining weight because you lack discipline.
👉 You are NOT gaining weight because you eat the wrong food.
👉 You are NOT gaining weight because you are lazy.

You are gaining weight because your hormones + metabolism + biology have changed.

Once your hormones improve…
Weight loss becomes much easier — without starving or over-exercising.

⭐ SUMMARY 

✔ Hypothyroidism slows metabolism massively
✔ Reverse T3 blocks fat burning
✔ Leptin resistance increases cravings
✔ Insulin resistance stores belly fat
✔ Inflammation adds extra weight
✔ Stress worsens everything
✔ It’s not your fault — it’s hormonal

📚 RESEARCH FACT-CHECK

Scientific References for Thyroid Weight Gain Claims

1- Low thyroid → slow metabolism:
Thyroid Hormone Regulation of Metabolism — shows hypothyroidism reduces energy use and fat breakdown.
🔗 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4044302/ PMC
2- Reverse T3 elevation in hypothyroid patients:
Reverse T3 in Patients With Hypothyroidism (PLOS ONE) — elevated rT3 seen in treated and untreated hypothyroid patients.
🔗 https://doi.org/10.1371/journal.pone.0325046 PLOS

- Leptin, insulin & metabolic effects:
Insulin resistance, leptin and thyroid metabolism — links hypothyroidism with leptin changes and insulin resistance.
🔗 https://pubmed.ncbi.nlm.nih.gov/314126236/ PMC

- Hypothyroidism & metabolic syndrome:
Subclinical Hypothyroidism in Obesity & Metabolic Syndrome — shows insulin resistance, metabolic changes and central obesity connections.
🔗 https://doi.org/10.3390/nu16010087 MDPI

- Inflammation & broader metabolic impact:
Thyroid Function & Metabolic Syndrome (Frontiers) — altered lipid, glucose metabolism and body composition in hypothyroid adults.
🔗 https://www.frontiersin.org/articles/10.3389/fendo.2021.661160/full Frontiers

- Cortisol & central fat storage:
Stress, Cortisol, and Obesity Review — shows cortisol’s role in increasing abdominal fat and changing energy balance.
🔗 https://pubmed.ncbi.nlm.nih.gov/27345309/ PubMed