These days, we’re encouraged to be “on” all the time: constantly bombarded with messaging about optimising, achieving, pushing harder, doing more. Protein is no different. High-protein diets have dominated nutritional advice (and marketing) for a hot minute, with protein being positioned as the answer to boosted energy, weight management, muscle retention, healthy ageing and steady blood sugar – so long as we consume it at every meal, in every snack, even in our drinks.
The thing is, protein is essential. It builds tissue, supports muscle, stabilises appetite, supports liver detoxification pathways and underpins immune and gut health. But that doesn’t necessarily mean consuming more of it is better.
Enter protein cycling: an approach I use with my clients to encourage contrast within the body (which can help with metabolic flexibility) and help them get the most out of their efforts to be healthy. Interestingly, the approach might involve eating less protein than you had been before. Allow me to explain.
What is protein cycling?
Protein cycling means intentionally alternating between periods of higher and lower protein intake. Rather than eating high protein every single day, it’s a flexible system that allows for variation. This is not about restricting, tracking, weighing or measuring food, rather it’s about creating a dynamic diet that allows the body to move between different metabolic states – building when it needs to build and resting when it needs to restore.
How does protein cycling work?
When you eat protein, particularly amino acids like leucine, you activate a pathway called mTOR (mechanistic target of rapamycin), which is a master regulator of growth. The pathway mTOR drives muscle protein synthesis (MPS), tissue repair, immune cell production, and many of the processes we associate with strength and robustness.
In healthy individuals, this rise in mTOR is short-lived. It will increase after a protein-rich meal, then return to baseline as amino acids are cleared from the bloodstream. Which is exactly how the system is meant to work. When growth signalling remains chronically elevated, access to the body’s other crucial mode – cellular repair – can become relatively suppressed. That repair mode is driven by pathways like AMPK and processes like autophagy. Autophagy is the body’s internal recycling system. It clears out damaged proteins, dysfunctional mitochondria, inflammatory debris and cellular waste, and is most active when growth signals are lower. You cannot build and clean efficiently at the same time.
Protein cycling works on the natural rhythm, allowing periods of higher and lower amino acid signalling to alternate, rather than keeping the system locked in one mode.
It’s important to note that protein itself is not the problem. The issue arises when growth signalling becomes chronically elevated because amino acid levels never meaningfully fall, which can happen when all meals, snacks and even drinks are protein-heavy. While mTOR is essential, it’s not meant to be permanently activated.
Why protein cycling is important
Protein cycling reintroduces a physiological pause. Having lighter, lower protein, more plant (fibre)-forward days means the system moves toward prioritising repair mode. We create contrast – we take our foot off the accelerator.
That contrast becomes more important as we go through our 30s, 40s, 50s, 60s and beyond, when insulin resistance and inflammation often rise and the body becomes less tolerant of constant metabolic pressure. This is particularly relevant for women, whose physiology is often more sensitive to stress, under-recovery and chronic metabolic load. Many women (and men) are not taking enough – or any – time to recover.
How to start protein cycling
For some people, protein cycling might look like two or three higher protein days, followed by a lower protein day. For others, every other day might work best. The actual rhythm is less important than the principle. It can be very helpful for those looking to support better metabolic flexibility, maintain steadier energy, improve insulin sensitivity, and reduce inflammation.
It’s a common misconception that you need to be consuming a constant stream of protein in order to maintain muscle mass. Your body is incredibly efficient at storing and utilising amino acids (which are the building blocks that make up protein). During periods of lower protein intake, your body can tap into these reserves to support essential functions, including muscle protein synthesis, which is when amino acids turn into muscle protein.
What to eat on higher protein days
In simple terms, a higher protein day might look like a portion (30g) of protein at each meal and strength-based movement. In more specific terms:
- A clear protein focus at each meal – eggs or a protein smoothie at breakfast, fish, meat, tofu or legumes at lunch and dinner;
- Resistance or strength-based movement – weights, Pilates, reformer, barre or anything that loads muscle and bone;
- A day that feels active, outward and building.
What to eat on lower protein days
A low protein day does not mean a low calorie day. It simply means shifting the emphasis away from dense protein towards plants, fibre and colour. More specifically:
- More plants, more colour, more fibre, more vegetables, fruit and whole foods;
- Soups, bowls, salads, root vegetables, small portions of legumes, nuts and seeds and less emphasis on dense animal protein;
- Gentler movement – walking, yoga, mobility, stretching, breathwork;
- A day that feels quieter, inward and restorative (heaven).
Who shouldn’t protein cycle
While it’s not extreme, people who are underweight, pregnant, breastfeeding, recovering from an illness or who have a history of eating disorders should check in with a professional. For most healthy adults, though, it’s a flexible way to work with the body.
