Just Diagnosed with Prediabetes? Your First 90 Days, Step by Step (UK)

A prediabetes diagnosis feels bigger than it is. You're not diabetic. Your blood sugar has been running high enough to show up in a three-month average, and your body is warning you while the warning is still cheap to act on. I ignored my warning and spent four and a half years on prescription medications because of it. Here's the ninety days I wish someone had laid out for me.

Week 1: get organised, not perfect

Before you change a single meal, do three things. First, get your actual HbA1c figure — 42 to 47 mmol/mol is the prediabetes range in the UK, and where you sit in it matters. Second, if you're in England, ask your GP for a referral to the NHS Healthier You Diabetes Prevention Programme — it's free and it works. Third, book your retest now, for around twelve weeks out. That date is your finish line, and having it in the diary changes how you behave in week six.

Then make exactly one change: close the kitchen after dinner. Nothing after your evening meal except water. For most people this is the single biggest source of hidden sugar in the day, and it costs you nothing but habit.

Weeks 2–4: the three big levers

1. Fibre before your two main meals. A fibre-rich drink in water, ten to fifteen minutes before lunch and dinner, slows the meal down and flattens the spike. It's the change that holds even on your worst days, because it takes thirty seconds and no willpower. I use Unicity Balance for this; the food-first version of the same idea is in what to eat for insulin resistance: a UK food guide.
2. Three meals, nothing between. No snacks. This is the hardest fortnight of the whole ninety days, and then it stops being hard. Every gap between meals is time insulin gets to fall — and falling insulin is the entire point.
3. Walk after one meal a day. Ten to twenty minutes, ordinary pace. Your muscles soak up blood sugar directly, and it measurably blunts the spike from the meal you just ate. After dinner is ideal because it also keeps you out of the kitchen.

Weeks 5–8: tighten the window

By now the grazing rule should feel normal. Next, compress your eating into a daily window — twelve hours is plenty to start, ten is better. Breakfast at eight, dinner done by six, that kind of shape. A yerba mate drink in the morning makes the longer gap before your first meal noticeably easier; I take Unimate first thing for exactly that reason. The mechanics of why the window works are in intermittent fasting explained.

Expect this period to feel flat. The scales may not move much, and nothing will feel different. This is where most people quit. Don't. HbA1c is a three-month average — the work you're doing in weeks five to eight is literally what the retest measures.

Weeks 9–12: hold, and let the average build

No new changes now. Hold the routine, keep the walks, protect your sleep — poor sleep measurably raises insulin resistance the next day, so this is part of the treatment, not a luxury. If you want to add one thing, add a little resistance work twice a week to protect muscle, because muscle is where blood sugar is supposed to go.

Day 90: the retest

Get the bloods done and ask for the figure, not a verdict. Whatever it says, compare it to your baseline, not to perfection. A drop from 46 to 43 is the process working — keep going. A drop below 42 is the official line back out of prediabetes. My own first meaningful movement came at day 90; the full timeline is in reversing prediabetes: what actually worked for me.

If you want the two-drink routine that held all of this together for me, it's explained plainly at the Feel Great system — and it carries a 90-day money-back guarantee, which is exactly the length of test you're running anyway.

I'm not a doctor and this isn't medical advice — it's one man's account of what worked, and your GP stays in the loop throughout. If you want to talk it through, message me — no pitch.