Growth hormone (GH) is often associated with childhood growth — but its most impressive work happens long after we stop growing. In adults, GH becomes a key metabolic hormone that supports fat loss, lean muscle preservation and overall metabolic flexibility.

GH is not released steadily. Instead, it’s secreted in powerful pulses, and the biggest pulse of the entire day happens at night — during deep, slow-wave sleep. This makes GH one of the most underestimated hormones in metabolic and weight-loss physiology.

Growth hormone is a peptide made in the anterior pituitary gland, a tiny structure at the base of the brain. While GH is crucial for bone and muscle growth in childhood, it plays an equally important role in adults by:

• Stimulating fat breakdown (lipolysis)

• Preserving lean muscle

• Regulating glucose and insulin balance

• Supporting tissue repair and recovery during sleep

  
  

Think of GH as the hormone that shifts the body into “restore and repair mode.”

How GH Is Produced and Released

GH secretion is coordinated between two brain regions:

• The hypothalamus, which releases GHRH (a hormone that tells the pituitary to release GH)

• The pituitary gland, which responds by releasing GH into the bloodstream

These signals occur in pulsatile bursts — roughly every 1–3 hours — but the most powerful burst happens within the first 90 minutes of sleep, when we enter deep slow-wave sleep.

At night, insulin is naturally lower, and GH is higher — an ideal state for fat burning.

What Stimulates GH Release

This is why eating late at night, snacking in the evening or training too close to bedtime can blunt GH release — insulin will outcompete GH.

What Inhibits GH (and Why It Matters)

Several common modern lifestyle factors suppress GH:

• High insulin and high blood sugar (frequent eating, snacking, sugary foods)

• Visceral fat (especially belly fat)

• Poor sleep or disrupted sleep cycles

• Ageing (pulses become smaller over time)

• Elevated free fatty acids (seen in insulin resistance and metabolic syndrome)

Visceral fat is especially problematic. As waist circumference increases, GH pulses become smaller and weaker, even if their timing remains intact.

Why Night-Time GH Matters for Fat Loss

During the night, GH and low insulin work together to burn fat.

Here’s what happens:

1. Insulin drops

2. GH surges

3. Stored fat is released as free fatty acids

4. The body uses fat for energy while sparing muscle tissue

This is called nocturnal lipolysis — literally fat-burning while you sleep.

Night-time GH also:

• Maintains metabolic flexibility (ability to switch between carbs and fat for fuel)

• Preserves lean muscle mass while losing weight

• Supports blood glucose balance

• Enhances tissue repair and recovery after exercise

When GH release is disrupted (poor sleep, late eating, high insulin), fat burning becomes impaired — even if your diet is “perfect” during the day.

How to Support Optimal GH Rhythm

You can boost GH naturally by:

✔ Prioritising early, consistent bedtimes

✔ Avoiding food 2–3 hours before sleep

✔ Training regularly (mix of strength + cardio intervals)

✔ Increasing protein and amino acids such as arginine

✔ Reducing visceral fat through nutrition and movement

Small changes in sleep habits can dramatically improve GH secretion — and fat loss.

If you’re struggling with stubborn weight gain, poor sleep or hormonal imbalance, you don’t have to figure it out alone.

Book a consultation to receive tailored nutritional, lifestyle and hormonal support based on your personal health profile.