Every week on the NHS Diabetes Prevention Programme, I meet someone holding a letter that says their HbA1c is between 42 and 47 mmol/mol. Most of them have read it as a diagnosis-in-waiting. Almost none of them have been told the more important truth: this is the stage where the condition is most responsive to change, and the changes required are smaller than they fear.
What the number actually says
HbA1c reflects your average blood glucose over roughly the last three months. The 42–47 band, known as "non-diabetic hyperglycaemia" or pre-diabetes, means your body is starting to struggle to manage glucose, usually because muscle and liver cells have become less responsive to insulin.
It does not mean progression is inevitable. Without changes, a meaningful share of people in this band do develop type 2 diabetes within a decade. With changes, the landmark prevention trials, the US Diabetes Prevention Program and the Finnish DPS, cut progression by around half, and the effect persisted for years after the programmes ended. That's not a marginal drug effect; that's one of the strongest results in lifestyle medicine.
The four levers, ranked by evidence
- Lose a modest amount of weight, if you carry excess. The prevention trials targeted just 5–7% of bodyweight. For a 90 kg person that's 4.5–6 kg, not a transformation montage. Visceral fat (around the organs) is the metabolically loud kind, and it's the first to respond.
- Move, especially with muscle. Muscle is your largest glucose sink. Brisk walking works; adding two or three resistance sessions a week works better, because trained muscle pulls glucose out of the blood without needing much insulin at all.
- Rebuild the plate, don't burn it down. More fibre (legumes, vegetables, intact grains), fewer refined carbohydrates and sugary drinks, protein at every meal. Plant-forward eating patterns consistently associate with lower diabetes risk, and no, fruit is not your enemy.
- Sleep and stress are not optional extras. Short sleep measurably worsens next-day insulin sensitivity. This lever gets ignored because it isn't sold in a supplement.
What I tell my own clients
Don't try to be perfect for three weeks. Try to be slightly better for three years.
The people I watch bring their HbA1c back into the normal range are almost never the ones who attempt a dramatic overhaul. They're the ones who pick two or three boring, durable changes (a daily walk after the largest meal, legumes replacing half the rice, a fixed bedtime) and let consistency compound.
Pre-diabetes is the fork in the road. Both paths are real. But the direction you take is, to an unusual degree in medicine, up to you, and the earlier you act, the easier the turn.
If you've just had a result in this range and want a plan built around your numbers, your food culture and your actual life, the first conversation is free. Book below.