- Aim for at least 25–30 g of fiber a day. Most adults eat far less.
- People who eat the most fiber have a 15–30% lower risk of early death and of several diseases, including type 2 diabetes.
- A rough protein guide for many adults is 1.0–1.2 g per kg of body weight a day, spread across meals.
- Eating vegetables and protein before carbs lowered the blood sugar rise by up to 37% in one study.
If you have prediabetes, what you eat alongside your carbs matters almost as much as the carbs themselves. Fiber and protein slow down digestion, so sugar from a meal enters the blood more gradually. They also keep you full for longer, which makes weight loss easier. The trouble is that many everyday meals, such as white rice with a thin curry, toast with jam, or a quick packet of noodles, are low in both. This guide shows how much you need and simple ways to get there.
Why fiber matters
Fiber is the part of plant foods your body cannot digest. Soluble fiber, found in oats, barley, beans, lentils, apples and psyllium, forms a gel in the gut that slows sugar absorption and helps lower LDL cholesterol. Insoluble fiber, found in whole grains, bran and vegetable skins, keeps your bowels regular. Both feed healthy gut bacteria.
Reynolds et al., Lancet 2019 (185 cohort studies and 58 trials); Whitehead et al., Am J Clin Nutr 2014.
The Finnish Diabetes Prevention Study, which cut diabetes risk by 58%, included a goal of at least 15 g of fiber for every 1,000 calories eaten. For most adults that works out to 25–35 g a day.
Where to get fiber
| Food and portion | Fiber (approx.) |
|---|---|
| Cooked lentils or dal, 1 cup (200 g) | 15 g |
| Cooked chickpeas (chana) or rajma, 1 cup | 11–13 g |
| Green peas, cooked, 1 cup | 9 g |
| Broccoli, cooked, 1 cup | 5 g |
| Pear or apple, with skin, 1 medium | 4–5 g |
| Rolled oats, ½ cup dry (40 g) | 4 g |
| Chia seeds, 1 tablespoon | 4 g |
| Almonds, a small handful (28 g) | 3.5 g |
| Brown rice, cooked, 1 cup | 3.5 g |
| Whole-wheat roti, 1 medium | 2–3 g |
| White rice, cooked, 1 cup | under 1 g |
Approximate values from standard food composition tables; actual amounts vary by recipe and brand.
Raise fiber slowly over 2–3 weeks and drink plenty of water to avoid bloating.
How much protein do you need?
The minimum daily allowance for adults is 0.8 g of protein per kg of body weight. Many experts suggest 1.0–1.2 g per kg for older adults, and a similar amount is a reasonable rough guide for people who are losing weight or building muscle, because protein helps protect muscle. For a 70 kg person, that is about 70–85 g a day. Spreading it out, with roughly 20–30 g at each main meal, works better than one big protein dinner. Learn more in The Complete Guide to Protein.
| Food and portion | Protein (approx.) |
|---|---|
| Chicken breast, cooked, 100 g | 31 g |
| Fish such as salmon, cooked, 100 g | 22–25 g |
| Paneer, 100 g | 18 g |
| Cooked lentils or dal, 1 cup (200 g) | 18 g |
| Greek yogurt, 170 g pot | 15–17 g |
| Soya chunks, 30 g dry | 15 g |
| Cooked chickpeas (chana), 1 cup | 14 g |
| Firm tofu, 100 g | 10–15 g |
| Milk, 1 glass (250 ml), or curd, 1 cup | 8 g |
| Egg, 1 large | 6 g |
| Peanuts, a small handful (28 g) | 7 g |
Approximate values from standard food composition tables.
Eat protein and vegetables first
The order in which you eat may matter too. In a small study of adults with type 2 diabetes, people ate the same meal of chicken, salad, vegetables, bread and orange juice on two days. When they ate the chicken and vegetables first and the carbs 15 minutes later, their blood sugar rose much less than when they ate the carbs first.
Lower blood sugar when protein and vegetables were eaten first
Shukla et al., Diabetes Care 2015 (11 adults with type 2 diabetes; results in prediabetes may differ).
In practice: start with a salad, sabzi or dal, and eggs, paneer or fish, then eat your rice or roti. It is a free, easy habit that may soften the post-meal spike.
Easy upgrades
More ideas are in Breakfast for Prediabetes and What to Eat with Prediabetes.
Check your own targets. Try our Fiber Calculator and Protein Calculator to see how your current meals compare.
Talk to your doctor or dietitian before raising protein if you have chronic kidney disease, as you may need a lower amount. If you have a bowel condition, ask before adding a lot of fiber, and if you take medicines, take fiber supplements such as psyllium a few hours apart from them.
MythVegetarians cannot get enough protein.
FactDal, chana, rajma, soya, paneer, curd, milk, tofu and nuts can easily cover protein needs when included at every meal.
Common questions
Are fiber supplements as good as food?
Psyllium can help with blood sugar and cholesterol, but whole foods also provide vitamins, minerals and plant compounds. Use supplements to fill a gap, not replace food.
Do protein shakes help prediabetes?
They are convenient but not necessary. Choose unsweetened options and check the label for added sugar.
Is too much protein harmful?
For healthy kidneys, intakes around 1.0–1.2 g per kg are considered safe. Very high intakes offer no extra benefit.
- Aim for 25–30 g or more of fiber daily from dal, beans, vegetables, fruit, oats and whole grains.
- A rough protein guide is 1.0–1.2 g per kg a day, spread across meals.
- Eating vegetables and protein before carbs may reduce the blood sugar spike.
- Small swaps at breakfast and snack time add up quickly.
- Next: Rice, Roti and Oats: Choosing Carbs When You Have Prediabetes.
Sources
- Reynolds A, Mann J, Cummings J, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019;393(10170):434–445.
- Shukla AP, Iliescu RG, Thomas CE, Aronne LJ. Food order has a significant impact on postprandial glucose and insulin levels. Diabetes Care. 2015;38(7):e98–e99.
- Whitehead A, Beck EJ, Tosh S, Wolever TM. Cholesterol-lowering effects of oat β-glucan: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2014;100(6):1413–1421.
- Bauer J, Biolo G, Cederholm T, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013;14(8):542–559.
- Tuomilehto J, Lindström J, Eriksson JG, et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med. 2001;344(18):1343–1350.
- American Diabetes Association Professional Practice Committee. 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1).
This article is for general education and is not a substitute for advice from your own doctor or healthcare team.