Diabetes, Waist Size and the Saudi Diet

What the research says

Start with how risk is measured. Waist-to-height ratio predicts diabetes and cardiovascular events better than BMI because it tracks visceral fat, and the simple rule, keep your waist under half your height, holds across populations; the cohort data on central fatness and mortality show why two people with the same BMI can carry very different risk. On what drives that fat, the largest studies are consistent: a 15-year follow-up of 11,733 adults linked high added-sugar intake to nearly three times the cardiovascular mortality, and the 2024 BMJ umbrella review of almost ten million people tied ultra-processed food to 32 adverse outcomes, including type 2 diabetes, as detailed in the chronic-disease evidence. On what protects, a 2025 Harvard analysis of 221,000 adults found each 5 g a day of olive oil associated with 8% lower mortality, the Mediterranean pattern cuts combined cardiovascular and diabetes risk by about a third in trials, and the fibre and gut-microbiome work explains why fibre’s benefit varies between people. For the national picture, 58% of Saudi adults have hypertension, diabetes or obesity, most of it preventable.

Why the Gulf is different

The Saudi food environment has changed faster than almost any in the world: within two generations, a diet of dates, wheat, legumes, lamb and laban has been joined by sugar-sweetened drinks at every meal, white rice in large portions, delivery apps and packaged snacks. The main meal is typically eaten late and in quantity, which the meal-timing research in the sleep pillar shows is the worst pattern for glucose control. Sun avoidance produces the vitamin D paradox, where one of the sunniest countries has some of the lowest levels, and vitamin D status affects insulin sensitivity. At the same time, the traditional pantry is unusually good: dates, pomegranate, olive oil and legumes are among the most-studied protective foods, so the fix is less about importing a foreign diet than about restoring proportions.

A practical plan

1. Measure your waist, not your weight. At the navel, relaxed. If it is more than half your height in centimetres, that is the number to move, and a 3–5 cm reduction is clinically meaningful.
2. Remove liquid sugar first. Soft drinks, juice, sweetened coffee and energy drinks are the single largest added-sugar source in the Gulf; swapping them for water, unsweetened laban or Arabic coffee removes 200–400 calories of sugar a day with no other change.
3. Half the plate vegetables, a quarter protein, a quarter starch. Rice and bread stay, but at a quarter of the plate, and preferably brown rice, bulgur or whole-wheat bread for the fibre effect on digestion and glucose.
4. Front-load protein. 25–35 g at breakfast (eggs, labneh, foul, chicken) blunts the glucose response for the rest of the day; see protein timing.
5. Make the big meal lunch, and make dinner early. Where that is impossible, keep dinner small and walk after it.
6. Add the protective foods deliberately. A tablespoon or two of olive oil a day, legumes four times a week, fish twice a week for omega-3, and dates in the two-to-three range rather than by the handful.

Common mistakes

• Relying on “diet” drinks: the sucralose and gut-bacteria findings suggest sweeteners are not metabolically neutral for everyone.
• Cutting all carbohydrate, then eating twice as much at the next social meal. Moderation holds; elimination rarely does in a culture built around shared food.
• Taking vitamins to compensate for a poor diet; the Saudi micronutrient data show that real gaps exist, but supplements do not undo sugar.
• Assuming GLP-1 medication replaces diet change; the side-effect profile and the regain data say otherwise.
• Ignoring the mood dimension: the SMILES trial showed dietary improvement treats depression, and low mood drives sugar intake in a loop.

When to seek medical help

Every adult over 35 in Saudi Arabia, and anyone younger with a waist above the half-height line or a family history of diabetes, should have fasting glucose and HbA1c checked; the national rate of undiagnosed diabetes is high. Excessive thirst, frequent urination, unexplained weight loss, blurred vision or slow-healing wounds warrant a prompt appointment. Anyone already on diabetes medication who changes their diet substantially should tell their doctor, because doses often need to come down as glucose improves.