Keto Diets, Artificial Sweeteners, and More

With all the media messages we get about weight loss and health, it’s easy to feel attacked, guilty, and confused about what and how to eat. That’s especially true for people with diabetes. To help cut through the noise, five controversial nutrition topics were addressed by two certified diabetes care and education specialists (CDCES) in a session of the 2022 American Diabetes Association (ADA) annual meeting last week in New Orleans. Following is a distillation of their comments.

The presenters were Maureen Chomko, RDN, CDCES, from Neighborcare Health in Seattle, and Alison Evert, RDN, CDCES, FADCES, from University of Washington Medicine, also in Seattle.

1. When and How Often Should You Be Eating?

It seems simple, but there are many questions about when to eat. Often people with diabetes are told to eat frequently—the “3 meals and 3 snacks” paradigm–—but this may not fit your lifestyle or the particular day you are having. Or maybe you are not hungry when a scheduled snack comes around. So is it okay to skip a meal or snack? What about missing breakfast?

Expert take: According to Chomko, there is no conclusive evidence on the effect of meal frequency on human health or on glucose management. Frequent eating may result in unnecessary calories or chronic hyperglycemia; on the other hand, larger and less frequent meals can produce hazardous fluctuations in glucose levels. Skipping breakfast may assist in glucose management later in the day for those who routinely skip it—but if you typically eat breakfast, skipping it may lead to compensatory calorie intake later in the day, like having an extra serving with dinner. This may increase risks, Chomko said.

For people with type 2 diabetes, Chomko noted that coordinating meals with medication is important. Medications don’t work unless they are taken, and taking certain meds with meals can reduce possible side effects such as nausea and hypoglycemia. Plus, coordinating medication with mealtimes in turn improves adherence.

For people with type 1 diabetes, a regular meal pattern with smaller but more frequent meals and no snacking has been associated with better glucose management, Chomko said. Other than that, there seem to be no one-size-fits-all rules about when or at what frequency to eat.

Related: Intermittent Fasting: A Powerful Tool to Treat Diabetes?

2. What should you be eating—that is, how much fat vs. protein vs. carbs?

According to the American Diabetes Association’s (ADA) 2019 nutrition consensus report:

“Evidence suggests that there is not an ideal percentage of calories from carbohydrate, protein, and fat for all people with or at risk for diabetes; Therefore, macronutrient distribution should be based on an individualized assessment of current eating patterns, preferences, and metabolic goals.”

Data from the National Health and Nutrition Examination Survey (NHANES) show that the energy intake of Americans over the last 20 years or so has been comprised of about 33% fat, 16% protein, and 50% carbohydrates.¹ These ratios are roughly the same in people with diabetes.² Regrettably, about 42% of the average person’s carb intake is low quality carbohydrates, or carbs that come from the likes of refined flour and sugar. They produce quick energy but have very little nutritional value.

Expert take: Work with your doctor or CDCES on the right mix of fat, protein, and carbs for your body, lifestyle, and diabetes goals. When you eat carbohydrates, make sure they’re mostly high-quality ones.

3. Are “net carb” counts on food labels meaningful?

While first coined in 1929 by RD Lawrence and R.A. McCance in the British Medical Journal,³ the term “net carbs” did not become part of the popular lexicon until Robert Atkins published his book “Dr. Atkins’ Diet Revolution” in 1972. On most food labels, the net carbohydrate is the amount of carbohydrates left after dietary fiber and sugar alcohols are subtracted out of the total carbohydrate value. This may lead a person to think they can eat more because they do not have to include the calories of the carbohydrates they subtracted out.

Expert take: Evert asserted that there are two problems that can arise when reading carb and “net carb” counts on labels. First, not all fiber is equal; insoluble fiber provides no carbohydrates but soluble fiber does, she noted. Nutrition labels do not tell you how much of the total fiber is soluble versus insoluble.

Secondly, sugar alcohols are not completely free from sugar and can affect pre- and postprandial glucose levels (glucose before and after eating, respectively). Furthermore, different sugar alcohols have different caloric values.⁴ For example, xylitol, which is abundant in sugar-free gum, has a mean caloric value of 2.6 cal/gram while maltitol, found in sugar-free chocolates, has 2.1 cal/gram .

Evert suggested that sugar alcohols should be included when determining insulin dosing. Her other tip for reading nutrition labels? Use them to find opportunities to eat more fiber. “Less math, more fiber,” she said.

4. What about ketogenic (keto) diets, aka very low carb diets?

The general rule of thumb for very low carbohydrate diets is to obtain 50% to 80% of total energy from fat, with the remaining calories coming from protein and, to a lesser extent, carbohydrates. Ketogenic diets specifically suggest less than 20 to 50 grams of carbs per day—that’s less than a cup of white rice. Keto diets have become popular among some people with diabetes as well as in the general population.

Expert take: Evert walked the audience through what happens on a very low carb/keto diet (VLCKD). In the first 3 to 6 months, people with diabetes will experience weight loss, reductions in glycemia, and improved A1C levels; They may also reduce their medication and insulin requirements. These effects do not last, Evert added. During the 6 to 12 month period all benefits become less pronounced and by 12 months there is no advantage of VLCKD over other diets, including low-fat, mid-carb, and low-glycemic-index diets.⁵ This may be in part because Study participants tend to fall away from strict dietary adherence to a VLCKD plan after about 5 months.

In the short term, Evert tells us that it is safe for most people with diabetes to try a VLCKD with careful monitoring by a health care professional to watch their insulin needs, changes in lipid panels, electrolyte levels, and microflora composition in the gut ( changes in this composition can lead to hold). If there is a medical need to lose weight quickly, as when a person is needing a knee replacement surgery and needs to lose weight before that, VLCKD can be a viable option for this.

A VLCKD is not Recommended for people with diabetes who are taking an SGLT2 inhibitor (such as empagliflozin, canagliflozin, etc.) or for anyone with an eating disorder or who is pregnant or seeking to become pregnant, Evert emphasized.

Because there is so little evidence on the long-term use of VLCKD in people with diabetes, whether Evert recommends that individuals talk to their health care professional about their long-term diabetes goals and VLCKD is the best option for reaching those goals.

5. Do artificial sweeteners help or hinder your health?

There is no simple answer. The human effects of artificial sweeteners (AS) are hard to isolate because of our complex and individualized diets, backgrounds, and environments. Each AS is differently metabolized.⁶ Sucralose is pretty much excreted in the same form it was ingested, while aspartame gets broken down into aspartic acid, phenylalanine, and methanol before being absorbed into the circulatory system from the intestine. To make it more complex, artificial sweeteners are not consumed in isolation but in combination with other ingredients in foods and beverages.

A meta-analysis of AS intake and cardiometabolic health published in 2017 in the Canadian Medical Association Journal concluded that the health benefits of artificial sweeteners remain unclear.⁷ On the other hand, AS consumption has been associated with unhealthy effects including increased cardiometabolic risk and a potential increase in body mass index (BMI) over time. The reason the results are so inconclusive is because the human diet studies are highly variable, from study length to the type of people studied and even who ran the study. For example, studies that suggest artificial sweeteners reduce BMI are largely industry sponsored, Evert pointed out.

The ADA and the American Heart Association agree that there is simply not enough evidence to support artificial sweeteners as a healthy alternative to sugar. The ADA states: ⁸

“Using sugar substitutes does not make an unhealthy choice healthy; rather it makes the choice less unhealthy.”

Expert take: Without clear direction on AS effects, Evert suggested that our best choice when it comes to these additives, at least in beverages, is to start by replacing one artificially sweetened drink with water, coffee, or unsweetened tea every day.

Bottom Line

Most diets work for some people and no diet works for all people. Chomko recommended that people with diabetes first decide what their main goal is when it comes to managing their diabetes: Lose weight? Manage glucose levels? Improve lipid profile? Lower blood pressure? Once that goal is identified, talk about it with your health care team. Engage in a shared decision-making process that can help you achieve those goals.

Take advantage of a registered dietician or diabetes educator (CDCES) to help you create a custom diabetes eating plan that works for you and that is sustainable for your lifestyle. Sustainability is key.

Then begins the task of getting to know your own body through trial and error; as Chomko put it, “be your own experiment.” If you hit on an eating plan that works for you, embrace it. If your diabetes goals change, explore a new plan. Be open, be proactive, and then simply be.

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  2. Oza-Frank R, Cheng YJ, Narayan KM, Gregg EW. Trends in nutrient intake among adults with diabetes in the United States: 1988-2004. J Am Diet Assoc. 2009 Jul;109(7):1173-8. doi: 10.1016/j.jada.2009.04.007. PMID: 19559133.
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  4. Felber JP, Tappy L, Vouillamoz D, Randin JP, Jéquier E. Comparative study of maltitol and sucrose by means of continuous indirect calorimetry. JPEN J Parenter Enteral Nutr. 1987 May-Jun;11(3):250-4. doi: 10.1177/0148607187011003250. PMID: 3298708.
  5. Kumar NK, Merrill JD, Carlson S, German J, Yancy WS Jr. Adherence to Low-Carbohydrate Diets in Patients with Diabetes: A Narrative Review. Diabetes Metab Syndr Obes. 2022 Feb 18;15:477-498. doi: 10.2147/DMSO.S292742. PMID: 35210797; PMCID: PMC8863186.
  6. Magnuson BA, Carakostas MC, Moore NH, Poulos SP, Renwick AG. Biological fate of low-calorie sweeteners. Nutr Rev. 2016 Nov;74(11):670-689. doi: 10.1093/nutrit/nuw032. PMID: 27753624.
  7. Azad MB, Abou-Setta AM, Chauhan BF, Rabbani R, Lys J, Copstein L, Mann A, Jeyaraman MM, Reid AE, Fiander M, MacKay DS, McGavock J, Wicklow B, Zarychanski R. Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. CMAJ. 2017 Jul 17;189(28):E929-E939. doi: 10.1503/cmaj.161390. PMID: 28716847; PMCID: PMC5515645.
  8. Evert AB, Dennison M, Gardner CD, Garvey WT, Lau KHK, MacLeod J, Mitri J, Pereira RF, Rawlings K, Robinson S, Saslow L, Uelmen S, Urbanski PB, Yancy WS Jr. Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report. Diabetes Care. 2019 May;42(5):731-754. doi: 10.2337/dci19-0014. Epub 2019 Apr 18. PMID: 31000505; PMCID

Dr. Bjugstad received her PhD in Neuroscience from the University of South Florida. During her time as a research scientist, she has published more than 40 peer-reviewed articles and given over 75 conference presentations on topics including Alzheimer’s disease, heart disease,tic brain injury and male infertility.

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