This chapter is about a tool that asks for none of that. It is a picture: a plate divided into three parts. It needs no scale, no app, and no reading of tables. A child can copy it, and it works in a home kitchen anywhere in the world, because it is built on proportions and not on particular foods. Whether your plate holds rice, roti, injera, tortillas, or potatoes, the shape stays the same.

We begin with the plate itself and what the evidence says about it. We then fill each of its zones, with examples from many cuisines. Finally we place the plate in the larger picture of eating patterns, look at what the research says about the popular ones, and cover the situations in which the basic plate needs adjusting.

6.1 The Picture: A Plate in Three Parts

One plate, three zones

The plate method, as promoted by the American Diabetes Association (ADA), starts with a nine-inch plate (about 23 centimetres) and divides it into three sections. Half the plate is filled with non-starchy vegetables. One quarter holds protein. One quarter holds carbohydrate foods. A glass of water or another drink with no calories goes beside it.[@adaplate]

That is the entire method. It is deliberately simple, because its purpose is to make the right choice the easy choice at every meal, including meals you have never eaten before.

{{fig:F6-A}}

Why this shape?

Each zone has a job. The vegetables fill the largest part of the plate with food that is high in volume and fibre and low in carbohydrate and calories. The protein gives fullness and keeps meals satisfying. The carbohydrate quarter limits the part of the meal that raises glucose the most. Together they turn the ideas from Chapters 1 and 5 into a habit: the amount of carbohydrate is limited by space on the plate, not by counting, and the quality of that carbohydrate is improved by what you choose to put in that quarter.

Diabetes educators used the plate method for years before the United States Department of Agriculture released its own "MyPlate" graphic in 2011, and it has been described in the professional literature as a tool for simplified meal planning within a healthy eating pattern.[@spectrum2017] What has been missing, until recently, is trial evidence. That is changing.

What the trials show

Three randomised trials, all from Asia, give a sense of how the plate method performs.

In a trial in Nanjing, China, 419 adults with type 2 diabetes were taught either a plate model (half vegetables, a quarter protein, a quarter carbohydrate) or traditional carbohydrate counting, and both groups had monthly visits with a dietitian for a year. HbA1c fell by 1.36 percentage points in the plate group and by 0.50 in the carbohydrate-counting group at 12 months. Weight loss did not differ significantly between the groups. The authors concluded that the plate model was at least as effective as counting over this period, and it took less education time (17 versus 39 minutes a month).[@zhang2022]

A second Chinese trial followed 456 people with newly diagnosed type 2 diabetes who did not yet need medicine, comparing a plate model with low-fat diet education, for a mean of about eight years. In this study, 36 percent of the plate group needed glucose-lowering drugs during follow-up, compared with 76 percent of the low-fat group, and HbA1c fell by 1.05 versus 0.32 percentage points.[@zhang2023]

A third trial, in the Philippines, compared a Filipino plate method with standard ADA nutrition education in 148 people with type 2 diabetes. Both approaches improved the food-group balance of meals and lowered glucose two hours after eating, with no meaningful difference between them; the follow-up was only a few days.[@montevirgen2022]

Science Corner: How much weight can these trials bear? Read these trials as encouraging, not conclusive. The Chinese trials were run in single countries and the comparison groups were carbohydrate counting or low-fat education, not "no advice". Results over eight years can reflect many things besides the plate. The Philippine study measured only a short-term effect. Taken together, the fair summary is that the plate method appears at least as good as more complex approaches for many people, and that its simplicity is a real advantage: a plan you can follow every day usually beats a better plan you abandon.

6.2 Filling the Zones

Half the plate: non-starchy vegetables

Non-starchy vegetables are those that give a lot of food for very little carbohydrate: leafy greens, broccoli, cauliflower, cabbage, carrots, tomatoes, cucumbers, peppers, green beans, mushrooms, aubergine (eggplant), okra, and many more.[@adaplate] The World Health Organization recommends at least 400 grams of fruit and vegetables a day for adults.[@whodiet] Filling half the plate with vegetables at your main meals helps you move toward that target. Cooked or raw, fresh, frozen, or canned without added sugar or salt, all can count.

One quarter: protein

The protein zone can be fish, poultry, eggs, tofu or tempeh, or other plant proteins, and, in smaller amounts, lean meat and dairy. Beans, lentils, and chickpeas can sit here too, but with a note: because legumes also contain carbohydrate, they have an effect on glucose.[@adaplate] If you find they raise your glucose, ask your care team whether to count them toward the carbohydrate quarter. European guidance advises people with diabetes to favour minimally processed plant foods and to minimise red and processed meat.[@easd2023] There is no need to give up meat entirely, but the plate works best when meat is one of several protein choices, not the automatic centre of every meal.

One quarter: carbohydrate foods

This quarter holds the starchy foods and fruit: rice, roti, bread, noodles, maize meal, potatoes, cassava, plantain, corn, peas, oats, fruit, and low-fat dairy.[@adaplate] Two ideas from earlier chapters apply here. First, the size of this quarter matters, because the glycemic load is quality times quantity (Chapter 5). Second, quality matters: European guidance emphasises intact whole grains, and at least 35 grams of fibre a day, and reports that milling and processing whole grains appear to reduce their benefit for glucose.[@easd2023] The WHO puts its fibre floor lower, at 25 grams a day.[@whodiet] Either way, choosing whole grains, legumes, and whole fruit over refined flours and juice moves in the right direction.

Fats and flavour

Fats are not a fourth zone on the plate, but they matter, because they are where much of the flavour comes from. European guidance recommends non-hydrogenated vegetable oils that are not tropical oils, and limiting saturated fat, and the WHO recommends that saturated fat provide no more than 10 percent of energy and trans fat no more than 1 percent.[@easd2023][@whodiet] In practical terms: cook with olive, rapeseed (canola), sunflower, or similar oils in modest amounts, use nuts and seeds as toppings, and be cautious with deep-fried food, pastries, and processed snacks.

What to drink

Water, unsweetened tea, or coffee are the simplest choices. Sugar-sweetened drinks are the easiest place to reduce added sugar: a meta-analysis of cohort studies linked one to two servings a day with a higher risk of type 2 diabetes (Chapter 3), and the WHO recommends that free sugars supply less than 10 percent of energy.[@malik2010][@whodiet] European guidance also advises eating whole fruit rather than drinking it as juice.[@easd2023] We look more closely at sweeteners and labels in Chapter 8.

Salt is worth a line here too. The WHO recommends less than 5 grams of salt (2 grams of sodium) a day, which is why the plate favours fresh and home-cooked food over heavily processed food.[@whodiet]

One plate, many kitchens

The plate is a proportion, not a recipe. Keep the shape, and use the food of your own kitchen. The table below shows how the same three zones look in six cuisines. These are illustrations of how to apply the idea and not prescribed menus.

The plate also adapts to the container. On a thali, a divided tray, or in a rice bowl, keep the same proportions: about half of the space vegetables, a quarter protein, a quarter starch. If a meal is a single mixed dish, such as a stew, a noodle soup, or a curry over rice, look at the ratio inside the dish and add a side of vegetables when the starch dominates.

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6.3 Beyond the Plate: Eating Patterns and Adjustments

There is no single best diet

Sooner or later, someone will tell you that one particular way of eating is the answer to diabetes. The evidence does not support that claim. The European Association for the Study of Diabetes concludes that a range of foods and dietary patterns are suitable for managing diabetes, and the review behind its recommendations found benefits in prevention trials for Mediterranean, Nordic, and vegetarian patterns.[@easd2023] A 2019 consensus report on nutrition therapy for adults with diabetes or prediabetes similarly found no single ideal split of carbohydrate, protein, and fat, and many eating patterns that can work; the common threads were minimising added sugars and refined grains and choosing minimally processed foods.[@evert2019] The ADA also presents the plate as a framework that can be adjusted to match any of the recommended meal patterns.[@adaplate]

The low-carbohydrate question

Low-carbohydrate diets attract the strongest opinions, so it is worth knowing what the best available evidence says. A systematic review and meta-analysis of 23 randomised trials with 1,357 people with type 2 diabetes compared low and very low carbohydrate diets with control diets. At six months, remission (defined as an HbA1c below 6.5 percent, regardless of medicine use) was more common with low-carbohydrate diets (57 percent versus 31 percent), and HbA1c was about 0.5 percentage points lower; there was more weight loss, and triglycerides and insulin sensitivity improved. But these advantages diminished by 12 months, data at 12 months were sparse, and when remission required stopping all medicine the benefit was small. The authors also noted that there is no standard definition of remission, saw some (not statistically significant) signs of worse LDL cholesterol and quality of life in two studies, and suggested that clinicians might consider short-term low-carbohydrate diets while closely monitoring and adjusting medicines.[@goldenberg2021]

That last point deserves emphasis. If you take insulin or a sulfonylurea (a class of tablets that can cause lows) and you sharply cut carbohydrate, your glucose can fall enough to cause hypoglycaemia. Medicine doses may need to change before you change your diet. This is why the plate in this chapter, with a moderate carbohydrate quarter, is a starting point, and why any bigger reduction should be discussed with your care team first.

The 2019 consensus report goes one step further and notes that reducing overall carbohydrate has shown the most evidence for improving glycemia and can be applied within a variety of eating patterns.[@evert2019] In other words, how much carbohydrate you eat matters most, and the pattern around it is largely a matter of what you can maintain and enjoy.

Science Corner: Why "sustainable" is a scientific word A short trial can tell us what happens in a few months. Diabetes lasts decades. A pattern that gives a great result at three months but that you cannot keep is worth less than a more moderate one you follow for ten years. This is one reason the trials on the plate method and the low-carbohydrate trials look so similar: in both, early improvements were larger than later ones. When you compare options, ask two questions: does it work, and can I live with it?

When the plate needs adjusting

The plate is a general starting point. Some situations call for a personalised plan from your care team or a registered dietitian:

• You use insulin at meals. Some insulin plans depend on counting the grams of carbohydrate in a meal. The plate can still be your foundation, but ask your team how to combine the two.
• You take medicines that can cause lows. Changes to how much you eat should be matched with a review of your medicines, as noted above.
• You are pregnant, or have gestational diabetes. Needs differ; follow your obstetric and diabetes team's plan.
• You have kidney disease. Protein, potassium, and salt may need adjusting.
• You are underweight, losing weight unintentionally, or have a history of disordered eating. Speak to your team before using any structured method that focuses on limiting portions.
• You are a child or teenager. Growing bodies need enough energy and nutrients, and plans should be developed with a paediatric diabetes team.

Eating in real life

Plates do not always come to you. At a restaurant, ask for extra vegetables in place of some of the rice, noodles, or fries. At a celebration, take a small serving of the special dishes and fill the rest with vegetables and protein. At a shared table, serve yourself the vegetables first, and eat slowly. On the road, look for a portion of protein and something with vegetables in it. None of these will be perfect; each is better than skipping the meal or giving up.

Key Takeaways

• The plate method divides a nine-inch (about 23 cm) plate into half non-starchy vegetables, a quarter protein, and a quarter carbohydrate foods, with water or another no-calorie drink.
• It needs no counting and works in any cuisine, because it is a proportion and not a list of foods.
• In trials in China and the Philippines, the plate method performed at least as well as carbohydrate counting or standard education, and was simpler to teach; longer and larger trials are still needed.
• Quality matters inside each zone: minimally processed plants, whole grains, legumes, fish, and vegetable oils in modest amounts, with less red and processed meat, added sugar, and salt.
• No single eating pattern is best for everyone. Mediterranean, plant-based, and lower-carbohydrate patterns can all work; the best is the one you can keep.
• Low-carbohydrate diets can help in the short term, but the benefits shrank by 12 months, and anyone using insulin or medicines that can cause lows should adjust them with their care team before cutting carbohydrate.

Action Points

1. Draw the plate. On a piece of paper or your phone, sketch a circle divided into half, quarter, quarter. Write examples of your own foods in each zone.
2. Serve your next dinner using the plate. Fill half with vegetables first, add the protein and then the carbohydrate, and note how you feel two hours later.
3. Choose one swap in the carbohydrate quarter. For example, replace white bread with a whole-grain or seeded version, or juice with whole fruit.
4. Replace one sweet drink a day with water or an unsweetened drink for a week.
5. Tell your care team what you are planning, especially if you use insulin or take medicines that can cause lows, so they can adjust your plan if you change how much carbohydrate you eat.

This book is intended for education and does not replace personal medical advice. If you have diabetes or take glucose-lowering medication, please consult your healthcare team before changing your diet, exercise, or treatment.