Intermittent Fasting: Giving Your Metabolism a Break

Following on from our article on inflammation, we wanted to look at another way our everyday choices can influence what happens inside our bodies: when we eat.

Inflammation, blood-sugar regulation, insulin sensitivity, body weight and metabolic health are closely connected. We often concentrate on what we eat – but perhaps we should also ask:

How often are we eating?

For many of us, eating begins shortly after waking and continues through meals, snacks and calorific drinks until late in the evening. Intermittent fasting introduces something remarkably simple: a regular period when we aren’t eating.

This doesn’t mean going days without food. It might simply mean finishing dinner at 7pm and not eating again until breakfast. Some people extend this into time-restricted eating, consuming their meals within a 10- or 8-hour window.

From storing energy to using it

After a meal, blood glucose rises and the pancreas releases insulin. Insulin is essential – it helps glucose move from our bloodstream into cells to be used for energy or stored for later.

As time passes without food, glucose and insulin levels fall and the body increasingly draws upon stored energy. This ability to move between incoming and stored fuel is sometimes called metabolic flexibility.

Problems can develop when our tissues become less responsive to insulin. With insulin resistance, muscle, liver and fat cells don’t respond as effectively, so the pancreas may produce more insulin to maintain normal blood glucose.

This can develop for years before blood glucose reaches the threshold for pre-diabetes or type 2 diabetes.

Genetics, visceral fat, physical inactivity, poor sleep and diet can all contribute. The good news is that regular exercise, maintaining muscle, improving sleep, losing excess body fat where appropriate and dietary changes can all help improve insulin sensitivity.

Where does intermittent fasting fit?

A period without food allows insulin levels to fall between meals and gives the body greater opportunity to access stored energy.

There’s also a very practical reason fasting can help some people manage their weight: there are fewer hours available in which to eat.

Reducing habitual evening grazing, snacks and calorific drinks may reduce overall energy intake without continually counting calories. Research into time-restricted eating has found modest improvements in weight, waist circumference and some measures of glucose and insulin regulation.

Fasting isn’t magic, however. What we eat still matters. An eight-hour eating window filled with ultra-processed food doesn’t become healthy because we fasted for the other sixteen.

What about inflammation?

This brings us back to where we started.

Chronic low-grade inflammation, excess visceral fat and insulin resistance are closely associated. Studies of intermittent fasting and time-restricted eating have found improvements in some inflammatory markers, although results vary and some benefits may be related to improvements in weight and metabolic health.

It reinforces the message from our inflammation article: food, movement, sleep, stress and body composition all influence our internal environment.

Don’t forget muscle

Muscle isn’t just about strength or appearance – it is metabolically important tissue.

Skeletal muscle is a major destination for glucose, and physical activity increases glucose uptake and can improve insulin sensitivity.

Maintaining and building muscle becomes increasingly important as we age, supporting metabolic health, physical capacity and independence. It’s another reason we encourage resistance and functional exercise alongside treatment and rehabilitation.

And what about GLP-1?

GLP-1 is another fascinating example of our own physiology. It is a hormone our bodies naturally produce, involved in blood-glucose regulation, insulin secretion, digestion, appetite and feelings of fullness.

You may recognise the name because some modern weight-loss medications mimic the actions of GLP-1. Intermittent fasting and GLP-1 are different physiological mechanisms, but both lead to a bigger question:

How can we work with the systems our bodies already possess to support a healthy weight, appetite and blood-sugar regulation?

We explore this in our separate article on weight loss and supporting our natural GLP-1 response, with contributions from our collaborating health coach Alison Staveley and hypnotherapist Samantha Philips.

Knowing what to do isn’t always enough

Most of us broadly know we should eat well, move regularly and sleep properly. Turning that knowledge into lasting behaviour can be harder.

Alison’s health coaching can help turn intentions into realistic, sustainable changes. Samantha’s hypnotherapy offers another approach where habits, cravings, stress or emotional associations influence eating behaviour.

Alongside this, our osteopathy, physiotherapy and rehabilitation team can help people become more comfortable and confident with movement and exercise.

Different approaches, but all potentially useful pieces of the same puzzle.

Does everyone need to fast?

No. Intermittent fasting is a tool, not a rule.

It may be inappropriate during pregnancy or breastfeeding, for people who are underweight or have a current or previous eating disorder, and with certain medical conditions. People taking insulin or glucose-lowering medication should seek appropriate medical advice before substantially changing their eating pattern.

Those training intensively or trying to build muscle also need to ensure they are still getting sufficient energy, protein and nutrients.
Interested in making a change? Give us a call if you’d like to book with Alison or Samantha.

Your Body Is Your Medicine Cabinet…

Next time, we’re looking at another incredibly powerful piece of our own physiology:

Why we sleep. Zzzzz…