What Should I Eat with Diabetes?
By Jeemin Kwon
Diabetes UK releases their 2018 nutrition guidelines for people with diabetes and prediabetes. What would diaTribe hope to see added to these guidelines?
“What do I eat if I have diabetes?”
It’s probably the most common question we get, and definitely the most-searched diabetes topic on Google. While it’s not surprising that nutrition and diet are a high priority for people with diabetes – and also people without diabetes! – what is remarkable is the amount of unreliable and conflicting information available on the web. For those who don’t know, there are still a lot of major questions and controversies about the science of nutrition, so it is both difficult and very important to help people answer this tricky question.
Of the many opinions and research on this topic, Diabetes UK has published an updated set of 2018 nutrition guidelines. These excellent and practical guidelines, drawn from a review of hundreds of published studies, moves away from a “macronutrient” approach (fats, carbs, proteins) by taking a food-focused approach. We’ve been really impressed with the detailed work that Diabetes UK have done and the excellence of the scientists who have sieved through the evidence to develop the guidelines.
The 62-page document is posted here. Here’s a quick overview of Diabetes UK’s conclusions:
Foods to eat more of: vegetables, fruit, lean meat, fish (particularly oily fish), whole grains, nuts, and legumes
Foods not to worry about: eggs, dairy (particularly fermented foods like yogurt, without added sugar), tea, and coffee
Foods to eat less of: red and processed meat, potatoes, salt, refined (processed) carbs, sugar-sweetened beverages; very notably, these guidelines have ruled that refined carbs increase risk for type 2 diabetes – a breakthrough conclusion not yet adopted by many other organizations!
diaTribe’s own views on nutrition are somewhat aligned with Diabetes UK, but we have gone one extra step to say that lower-carb is better for day-to-day diabetes, and likely in the long run too. Diabetes UK’s guidelines are a little more conservative in that they acknowledge low-carb isn’t harmful, but they don’t say that it’s beneficial either. Specifically, diaTribe’s view is that:
Reducing carb intake to around 100 grams per day (less than 30 grams at one time) can be particularly helpful for those trying to stabilize their blood sugars
Since whole grains (e.g., granola, bread, rice, pasta) and sugary fruits (bananas, pineapples, apples, etc.) often contain a lot of carbs, avoiding them could be beneficial
Diabetes UK’s guidelines are a summary of existing nutrition research, which also serves as a reminder of the biggest thing this field needs: more robust trials, especially using continuous glucose monitoring to compare different carb intakes. For answers to common food FAQs, see Diabetes UK’s opinions below. Click here for their full guidelines.
Diabetes UK: Low-carb diets may help reduce the need for diabetes medications. Though research studies haven’t been able to decide what a recommended ideal carb amount is, there is growing evidence that reducing carb intake is safe and effective for people with type 2 trying to lose weight. For people with type 1, it depends on who you talk to, but Diabetes UK did not find any evidence supporting long-term efficacy of low-carb diets. That said, they also did not find any evidence suggesting that low-carb is harmful either.
Editor’s Note: In the past month, a study also appeared in Pediatrics sharing the benefits of low-carb in 316 people with type 1 diabetes. More research is clearly needed here, but we’re optimistic it will come. Adam Brown, our senior editor, has personally found low-carb to be extremely successful for stabilizing blood sugars and increasing time spent in-range (70-180 mg/dl). Read about his experience here and get more in his book, Bright Spots & Landmines: The Diabetes Guide I Wish Someone Had Handed Me.
Diabetes UK: Eating foods with a high glycemic index (GI, a measuring system from 0 to 100 that describes how much carbs raise blood sugars after eating) has been linked to higher A1C levels. Click here to look up GI levels of different foods. Some high GI foods to avoid include white bread, white rice, pasta, potatoes, pineapples, corn flakes, and instant oatmeal.
Diabetes UK: The evidence behind fat and different kinds of fat is inconclusive, but the Diabetes UK nutrition guidelines still recommend reducing saturated fat, which translates to eating less butter and red meat, on the basis that eating too much food high in saturated fat might increase the risk of heart disease. For years, we have been told that red meat and saturated fat are bad, but the consensus is slowly changing as more data comes in. There are now ‘good fats’ and even saturated fat is no longer considered quite as bad as it used to be. Diabetes UK is playing it safe for now, based on the preponderance of evidence.
Editor’s Note: Diets high in saturated fat also tend to be high in processed carbs and sugar, muddling the associations. Low-carb diets, even if they have some saturated fat, also tend to improve HDL and triglycerides, which could improve cardiovascular risk. Clearly more research is needed here.
Diabetes UK: While there are currently no specific daily sugar amounts for diabetes management, people with diabetes are encouraged to reduce sugar intake. In the UK, the recommended daily allowance for added sugar is 30 grams per day. (For reference, a 12 oz. can of Coca Cola has 39 grams of sugar.) Sugar-sweetened beverages in particular have been linked to weight-gain and other cardiometabolic risk (risk for diabetes, heart disease, or stroke) factors.
Though artificial sweeteners are an alternative, research has not found that they are effective in weight loss efforts, and has suggested that they may actually lead to weight gain in the long run.
Diabetes UK: The guidelines acknowledge that very low energy diets – eating less than 800 calories per day – are effective for weight loss, but do not recommend that they go longer for 3 months at a time.
Diabetes UK: Moderate amounts of alcohol are okay. A moderate amount here is defined as 14 units of alcohol per week, which translates to seven pints of average-strength beer or about nine glasses (125 mL) of average-strength wine per week.
Diabetes UK: Historically, the Mediterranean diet and DASH diet have been recommended for people with heart disease. A well-known feature of both diets is reducing salt intake (usual recommendation is less than 6,000 mg a day) and reducing saturated fat. Though both encourage somewhat high levels of carbohydrate per day, putting the Mediterranean diet and DASH diets at odds with the overall guidelines, both approaches have been shown to improve outcomes. The guidelines do note that one study found increased risk for heart disease with diets high in carb intake.
Diabetes UK: Fasting can increase the risk for both hypoglycemia and hyperglycemia. It is highly recommended to consult with a healthcare provider to create an individualized plan before fasting. Click here for “Ramadan and Diabetes: a guide for patients,” created by the Muslim Council of Great Britain.
Diabetes UK: There is little research to show that commercially available food products “for diabetics” has any benefit.
Diabetes UK: The research on fiber is limited but growing. Some studies suggest eating more fiber can help reduce A1C. While there is no strong evidence supporting specific fiber recommendations, it is likely that eating at least 30g a day is beneficial for blood sugar management. Most vegetables, fruit, nuts, and legumes are all high in fiber!