Foods That Raise and Lower Type 2 Diabetes Risk

Diet advice for diabetes prevention often gets reduced to “eat less sugar, eat more vegetables” — true, but vague. Two large bodies of research have gone further and actually quantified how much specific foods shift type 2 diabetes risk, expressed as risk ratios where 1.0 is the baseline, above 1.0 means increased risk, and below 1.0 means reduced risk.

Here’s what the numbers say, food by food.

Foods that increase risk

An umbrella review published in Nutrients (2020) pooled findings across multiple meta-analyses to rank the foods most consistently linked to higher type 2 diabetes risk:

Sugar-sweetened beverages topped the list — and the relationship is dose-dependent, not a simple on/off switch. The same research shows estimated relative risk climbing toward 1.5 as intake approaches 800ml per day, meaning the risk keeps building the more you drink, without a plateau in the range studied.

Red meat follows a similar dose-response curve, with relative risk approaching 1.5 at around 200g per day. Processed meat is the steepest of the three: relative risk rises toward 1.6 by roughly 150g per day, and while it appears to plateau somewhat around 40-50g per day, it continues climbing beyond that point rather than levelling off for good.

Worth noting: artificial sugar (non-nutritive sweeteners) appears on this increased-risk list too, at a risk ratio of 1.25 — a reminder that swapping sugar for artificial sweeteners isn’t automatically the risk-free choice it’s often assumed to be.

Foods that reduce risk

A separate systematic review and meta-analysis of prospective studies, published in the European Journal of Epidemiology (2017), looked at the other side of the ledger — food groups associated with lower risk:

Coffee shows the strongest single association in this dataset, at a risk ratio of 0.65 — a finding substantial enough that it’s covered in more depth in its own right elsewhere. Whole grain is the standout among actual foods eaten in meaningful quantity, with a risk ratio of 0.77, and its dose-response curve is notably steep: risk drops sharply and reaches its lowest point by around 50g per day, then stays low with further intake. Refined grains show the opposite pattern entirely — their risk ratio climbs steadily upward, passing 1.3 by around 700-800g per day, underlining that “whole” versus “refined” is not a minor technicality.

Fruit and vegetables both show a U-shaped dose-response relationship rather than a straight line. Vegetable intake reduces risk most around 250-300g per day, dipping to a risk ratio of roughly 0.88, while fruit follows a similar curve with its lowest point (around 0.87) at roughly 200-300g per day. In both cases, risk starts creeping back toward baseline at much higher intakes (600g per day and beyond) — evidence that more isn’t always simply better, and that there’s a sensible middle range rather than an unlimited upside.

Reading the two lists together

Put side by side, the two datasets tell a fairly coherent story: ultra-processed and sugar-heavy items (sweetened drinks, processed meat) carry the clearest upward risk, while whole, minimally processed foods — whole grains especially — carry the clearest downward benefit. Dairy in its various forms (low-fat dairy, yogurt, milk) consistently lands on the protective side too, alongside olive oil.

Frequently asked questions

Is any amount of sugar-sweetened beverage safe? The dose-response data shows risk increasing progressively from low levels of intake right up to 800ml per day, without an identified safe threshold in the studied range — so less is consistently better than more.

Are artificial sweeteners a safe swap for sugar? Not according to this data. Artificial sugar carried its own increased risk ratio (1.25) in the same umbrella review, comparable to processed meat.

Is more fruit and vegetable intake always better? Not indefinitely. Both showed a U-shaped curve, with the lowest risk in a moderate intake range (roughly 200-300g/day for fruit, 250-300g/day for vegetables) before ticking back up at much higher intakes.

This article is for general information only and does not constitute medical advice. If you have a diagnosed diabetic or prediabetic condition, consult your doctor or dietitian before making significant dietary changes.