2002NEJM
Diabetes Prevention Program
3,234 adults with prediabetes
Losing 7% of body weight and doing 150 minutes of activity a week cut new diabetes by 58%; the drug metformin cut it by 31%.
Find on PubMed ↗Research library · Food & life
Blood sugar: keeping the spikes in check
Years of high blood sugar damage blood vessels, nerves, eyes and kidneys. More than 1 in 3 adults in the US has prediabetes and most don't know it. The good news: daily habits beat medicine at stopping it from becoming diabetes.
Strong evidence−58%new diabetes in people with prediabetes who lost 7% of their weight and walked 150 min a weekDPP 2002, NEJM, 3,234 people
−26%deaths over 30 years after a 6-year lifestyle programmeDa Qing study, Gong 2019, Lancet Diabetes Endocrinol
2–5 minof light walking after a meal is enough to blunt the sugar spikeBuffey 2022, Sports Med, meta-analysis
01
The basics
How your body handles sugar
When you eat carbohydrates, they're broken down into glucose (sugar) that enters your blood. Your pancreas releases insulin, a hormone that works like a key, opening cells in your muscles, liver and fat so glucose can move in and be used or stored.
With too little activity, too much belly fat and poor sleep, cells start to ignore insulin. This is insulin resistance. The pancreas pumps out more and more insulin to compensate, often for 10 years or more, before blood sugar finally rises. First comes prediabetes, then type 2 diabetes.
Muscle is the biggest place glucose goes after a meal, and working muscles can take up glucose even without insulin. That's why walking after meals and strength training are so effective.
A walk after eating flattens the spike
Illustration of blood sugar after the same meal. Light walking soon after eating helps muscles pull sugar out of the blood.
02
How it works
From meal to muscle
1
Meal
Carbohydrates are digested into glucose, which enters your blood.
2
Insulin released
The pancreas sends insulin to unlock cells.
3
Muscles take it in
Most glucose is stored in muscle; moving muscles pull in even more.
4
Liver & fat store the rest
Excess is stored in the liver or turned into fat.
03
Measure it
Which tests to ask for
- HbA1c: shows your average blood sugar over the past 2–3 months. No fasting needed.
- Fasting glucose: after 8+ hours without food. 70–99 mg/dL (under 5.6 mmol/L) is normal; 100–125 (5.6–6.9) is prediabetes.
- Fasting insulin: not routine, but a high value can reveal insulin resistance years before sugar rises.
- Continuous glucose monitors (CGMs): a sensor on your arm shows how your blood sugar responds to meals in real time. Useful for learning, not needed by everyone.
Try your number
NormalPrediabetesDiabetes range
4.58
American Diabetes Association cut-offs. Diagnosis needs a doctor and usually two tests.
04
What the research says
The key studies
2015Lancet Diabetes Endocrinol
DPP Outcomes Study
Most of the original DPP group, 15 years
Fifteen years on, the lifestyle group still had 27% less diabetes.
Find on PubMed ↗2019Lancet Diabetes Endocrinol
Gong et al. (Da Qing)
577 adults in China, 30 years
Six years of diet and exercise delayed diabetes by about 4 years and cut heart events and deaths by about a quarter over 30 years.
Find on PubMed ↗2022Sports Medicine
Buffey et al.
7 studies
Even 2–5 minutes of light walking after eating lowered blood sugar compared with sitting. Standing helped a little.
Find on PubMed ↗2015Diabetes Care
Shukla et al.
11 adults with type 2 diabetes
Eating vegetables and protein before carbohydrates cut the blood sugar rise after a meal by about a third.
Find on PubMed ↗2018Lancet
Lean et al. (DiRECT)
306 people with type 2 diabetes
Nearly half went into remission after a structured weight-loss programme, showing type 2 diabetes can often be reversed.
Find on PubMed ↗05
Take action
How to keep blood sugar steady
Small habits around meals make a surprisingly big difference.
- 1
Walk after meals
10 minutes after your biggest meals; even 2–5 minutes helps.
- 2
Eat in the right order
Vegetables and protein first, starchy foods last.
- 3
Choose slow carbs
Whole grains, beans and lentils over white bread, rice and sugary cereal.
- 4
Drop sugary drinks
Soft drinks and juices are the fastest way to spike blood sugar.
- 5
Lift weights
More muscle means more space to store glucose.
- 6
Sleep and lose a little
Losing 5–7% of body weight and sleeping 7+ hours both improve insulin sensitivity.
06
Myth or fact
Common myths, checked
✕ MythEating sugar directly causes diabetes.
✓ FactType 2 diabetes is driven mainly by excess body fat, inactivity, genes and age. Sugary drinks raise risk through weight gain and liver fat.
✕ MythPeople with diabetes can't eat fruit.
✓ FactWhole fruit has fibre and is linked to lower diabetes risk. Juice is the problem.
✕ MythEveryone needs a glucose monitor.
✓ FactThey're helpful for learning but not needed for most healthy people.
✕ MythPrediabetes isn't serious.
✓ FactIt raises heart risk already, and up to 70% of people with it eventually develop diabetes without changes.
07
Questions
Frequently asked
How often should I get tested?
Every 3 years from age 35 (earlier if overweight or with family history). Yearly if you have prediabetes.
Is a sugar spike after a meal bad?
Some rise is normal. Big, frequent spikes and slow returns to baseline are what matter.
Does artificial sweetener help?
Swapping sugary drinks for diet ones helps short term. Water, tea and coffee are better long-term habits.
08
Sources
References and related topics
- Diabetes Prevention Program (2002). NEJM. 3,234 adults with prediabetes. PubMed ↗
- DPP Outcomes Study (2015). Lancet Diabetes Endocrinol. Most of the original DPP group, 15 years. PubMed ↗
- Gong et al. (Da Qing) (2019). Lancet Diabetes Endocrinol. 577 adults in China, 30 years. PubMed ↗
- Buffey et al. (2022). Sports Medicine. 7 studies. PubMed ↗
- Shukla et al. (2015). Diabetes Care. 11 adults with type 2 diabetes. PubMed ↗
- Lean et al. (DiRECT) (2018). Lancet. 306 people with type 2 diabetes. PubMed ↗