Healthy ageing and fasting: what do we know?

Ageing and metabolism are closely linked. The 5 Day Fast programme is a nutrition and exercise approach that mimics certain effects of fasting. Research into fasting looks at mechanisms associated with ageing. 

How does 5 Day Fast influence mechanisms involved in ageing?

5 Day Fast is based on controlled calorie restriction, where research investigates biological processes associated with healthy ageing.

The most researched mechanisms include:

• a temporary reduction in mTOR activity, linked to cellular growth

• the activation of autophagy, a cellular “clean-up” process

• improved insulin sensitivity

In practice, this means your body temporarily switches to a phase where damaged cellular parts are broken down and recycled.

This process helps limit the build-up of cellular damage (1), an important factor in ageing.

However, these effects are temporary. That is why the period after the programme is crucial. It is during this phase that your body can rebuild tissues under more favourable conditions.

💡 Take mTOR, for instance. By temporarily reducing its activity, your body shifts from a state focused on growth to one focused on repair. This supports processes like autophagy. During the period after the programme, mTOR activity rises again and protein synthesis resumes. Some research suggests that this response may occur more efficiently following a period of fasting.

What happens in the period after 5 Day Fast?

Research into fasting mimicking looks not only at the fasting period itself, but also at the period afterwards.

After the 5 days, you return to eating normally and your body rebuilds. Research into this rebuilding phase looks at things like:

• repair and rebuilding processes in cells

• protein synthesis getting going again

• how your body switches back to normal nutrition

These biological processes are linked in various studies to mechanisms involved in healthier ageing (2).

This also means that fasting alone isn't enough. It's precisely the combination of temporary fasting followed by recovery and rebuilding that this research investigates.

Why are metabolic health and ageing linked?

Good metabolic health plays an important role in ageing healthily.

Research into fasting mimicking looks, among other things, at:

• insulin sensitivity

• inflammatory markers

• metabolic flexibility

These studies use specific protocols and participant groups, so they don't tell you what 5 Day Fast will do for you. Results vary from person to person (3).

Overview of key effects:

When can 5 Day Fast support healthier ageing (and when not)?

How you experience 5 Day Fast depends largely on how you do it, both during and after the programme.

When might you want to do 5 Day Fast?

5 Day Fast suits you best if you:

• repeat it periodically

• build up properly in the period after 5 Day Fast and choose which habit you want to change structurally

• continue to eat enough protein afterwards

What are the limitations and points to watch?

On the other hand, it may be less effective if you:

• reintroduce food poorly in the period after 5 Day Fast 

• keep your calorie intake too low after the 5 days 

• already have high overall stress levels, or you're ill/injured

💡 Experimental or poorly executed forms of fasting, especially when applied over a longer period, can cause the opposite effect of what was originally intended. And therefore work against your health.

Who is 5 Day Fast for in relation to healthier ageing?

This programme is interesting for:

• people who want an evidence-based way to address mechanisms involved in ageing

• people looking to improve their metabolic health (how you convert nutrients into energy)

• people who are actively mindful of their health and ageing

However, it is less recommended:

• if you're dealing with severe fatigue

• if you're under a lot of stress

• when your recovery needs are increased (injury, illness, recovery period)

Can 5 Day Fast slow down ageing?

Fasting doesn't directly slow down ageing. Research does, however, look at mechanisms associated with healthy ageing.

What makes the difference:

• what changes in your body during the 5 days

• what you can maintain and carry forward after the 5 days

• repeating 5 Day Fast periodically, whenever it suits you

If 5 Day Fast fits into your life from time to time, it can be part of a healthy lifestyle. The programme isn't suitable for everyone, so check first whether it's right for you. Results vary from person to person.