Individuals living with diabetes, those at risk for diabetes, and healthcare professionals involved in diabetes management are currently riddled with information and misinformation on nutrition.

In a mini-symposium presented at the 82^nd Scientific Sessions of the American Diabetes Association (ADA), Maureen Chomko, RD, CDCES, and Alison Evert, MS, RDN, CDCES, discuss five key controversies surrounding nutrition in patients with diabetes.

Meal and snack frequency

Dietary recommendations often emphasize the importance of individualized meal planning, but there is very little research or consensus on meal and snack frequency. The effects of meal frequency on overall health and glucose management remain poorly understood.

In patients with type 2 diabetes (T2D), three meals plus three snacks daily may deliver unnecessary calories, and frequent eating may result in chronic hyperglycemia. On the other hand, eating sizeable but infrequent meals may cause large fluctuations in glucose levels. In patients with type 1 diabetes, a regular meal pattern with small but frequent meals and avoidance of additional snacks may help with glucose management.

Ms Chomko states that skipping breakfast and eating large dinners late at night are detrimental habits that may increase cardiovascular and cardiometabolic risk. Although there is a growing interest in time-restricting eating patterns, such as intermittent fasting, we need more rigorous evidence on its efficacy, mechanisms, and sustainability.

Macronutrients

Dietary assessment data in the US show that ~50% of calories come from carbohydrates, ~16% from proteins, and ~33% from fat. Up to 42% of the carbohydrate intake continues to come from low-quality carbohydrates.

Large systematic reviews by the ADA (2012) and the Academy of Nutrition and Dietetics (2017) found no optimal mix of carbohydrate, fat, and protein for patients with diabetes.

The ADA nutrition consensus report suggests that macronutrient distribution should be based on an individualized assessment of eating patterns, preferences, and metabolic goals. Individualization of the macronutrient composition will depend on the health status and the metabolic goals of patients with diabetes. Ms Chomko recommends utilizing a “shared decision-making” approach with an educated and informed patient.

Net carbs and fibers

Net carbs loosely refer to the subtraction of those carbohydrates that are not digested by the body or digested but not converted into glucose. Dietary alcohols and fibers are primary examples of these carbohydrates.

But the fact remains that not all fibers are created equal. We know that insoluble fiber does not contribute any calories; however, it is not clearly understood how much carbohydrates and calories are derived from digested soluble fiber. Most food labels fail to provide a breakup of soluble and insoluble fiber. Similarly, not all sugar alcohols are created equal. Despite claims by food manufacturers, sugar alcohols do affect postprandial blood glucose response.

So, the assumption that the blood glucose response from all fibers and sugar alcohols can be easily predicted and will have a similar effect on all individuals is not true.

Ms Evert recommends that patients using diet and exercise and/or non-insulin therapies should stop the practice of subtracting fiber and look for opportunities to eat more fiber. Patients using insulin plans should use total grams of carbohydrate and monitor pre- and postprandial glucose when consuming high-fiber foods or sugar alcohols.

It is important for clinicians to educate patients about the glycemic effects of sugar alcohols and monitor gastrointestinal effects of sugar alcohols, such as osmotic diarrhea.

Artificial sweeteners

The first caveat of artificial sweeteners is that they differ in terms of absorption, distribution, metabolism, and excretion.

The second caveat of artificial sweeteners is that they are not consumed in isolation. Diet sodas and extravagant sugar-free desserts may comprise more than one artificial sweetener. Furthermore, artificial sweeteners are becoming increasingly common in our household products, for example, in toothpaste.

The third caveat of artificial sweeteners is that it is challenging to isolate the effects of individual artificial sweeteners within complex diets, backgrounds, and environments of individuals.

A meta-analysis of randomized controlled trials found no significant effect of artificial sweeteners on body mass index (BMI), suggesting no benefit in weight loss. Rather, a meta-analysis of cohort studies found a slight increase in BMI, suggesting a risk for modest, long-term weight gain with artificial sweeteners. The analysis of cohort studies also found increased risks for hypertension, metabolic syndrome, T2D, and cardiovascular events associated with the use of artificial sweeteners.

In conclusion, artificial sweeteners may have potential adverse effects, but their underlying mechanisms are not clearly known, and the adverse effects may offset any potential benefit that these sweeteners provide.

Safety of low carbohydrate/ketogenic diets

A very low carbohydrate/ketogenic diet (VLCKD) incorporates high quantities of fat (50%-80% calories), moderate intake of protein, and a low but inconsistent intake of carbohydrates (10%-26% of total energy).

For patients with diabetes and a family history of or known dyslipidemia/cardiovascular disease, it is essential to obtain a baseline lipid panel before starting a VLCKD, followed by follow-up lipid assessments 4-12 weeks later to ensure no significant increase in low-density lipoprotein cholesterol.

For patients using insulin and sulfonylureas, a dose reduction is recommended to prevent hypoglycemia upon starting a VLCKD. Sodium-glucose cotransporter-2 inhibitors should not be used while on a VLCKD because of the possibility of euglycemic diabetic ketoacidosis. Hypovolemia is a concern with VLCKD in patients using diuretics; hence, it is important to ensure that they consume enough sodium and potassium.

Other potential safety concerns associated with VLCKD include risks for kidney stones, osteoporosis, constipation, hypothyroidism, and disordered eating. Additionally, there are concerns that VLCKD may have negative effects on the gut microflora composition.

In conclusion, Ms Evert states that VLCKD may be safe for most people with diabetes in the short term with medication adjustments and regular laboratory monitoring. The long-term safety of VLCKD needs further investigation.

ADA 2022 — Five controversies on nutrition in patients with diabetes

November Challenge

Topic Challenges