Fad Diets & Patients with Type 2 Diabetes

Dr. Anderson:
Welcome to Diabetes Discourse on ReachMD. I’m Dr. John Anderson, and today I’m sitting down with Dr. Kathleen Stanley, a registered dietitian and a certified diabetes educator with the Baptist Health Center in Kentucky, to discuss all kinds of fad diets. Welcome, Kathleen. 

Dr. Stanley:
Thank you for having me today, John.

Dr. Anderson:
Kathleen, are there any latest, truly new, fad diets out there that we’re hearing about?

Dr. Stanley:
If we look at what is a good, healthy eating guideline for the average adult American, we first go back to the 2015, 2020 healthy guidelines. And in these guidelines, it promotes healthy food choices, such as encouraging intake of fruits, vegetables, lean protein, whole grains, healthy oils, and limiting saturated and trans fats and added sugars. But it doesn’t necessarily address specific amounts of carbohydrate, protein and fat.

If we look at the RDA for carbohydrates, for instance, it’s listed as having a recommendation of approximately 130 grams per day for most age categories. Of course there’s going to be more for pregnancy, and other special considerations. And truly, the observed intake for people with Type 2 diabetes, if you look at the literature, is pretty modest. The average Type 2 person with diabetes is eating about 45% of their total calories from carbohydrate sources. Yet because carbohydrates cause the fastest rise in glucose after consumption, carbohydrates have long since been a target of speculation, as far as something we need to really, really restrict. And the low carbohydrate diets is something we hear often about.

This type of approach is still being researched as far as long-term safety, and while it might have some short-term benefits, we’re still waiting for those long-term studies and recommendations to become available. There are some concerns about low carb eating, in terms of an overall nutrition plan, because they may not meet micronutrient requirements for vitamins, such as C, A and B, due to the individual cutting back very strongly on fruits and vegetables, and bread products, and it may also not meet fiber recommendations. It also may not be very palatable long-term, and if you think about it, how often do you see, like in a nursing home, would there be an offering to have a low-carb diet choice? That’s not really practical in a lot of different settings, so it’s not something that’s widely adaptable for different lifespan categories. And then, what happens when we replace the carbohydrate foods? If we’re eating low amounts of carbohydrates, we’re filling that up, likely, with protein or fat choices. And with protein, there’s not a lot of evidence that’s showing that this is a good thing for our kidneys and our cardiovascular system. So even though we see the low-carb approach being used, there’s a lot of questions that come out of it.

The protein, I’ve just touched lightly on, we’re not really sure if it has a negative impact long term, but on the short term, if we increase our intake of proteins – even if they’re plant-based proteins, such as nuts – we’re still going to probably get a significant source of fat from that product. And while it may be a healthier fat choice, it is still a fat, and an increased intake of fat may increase the risk of cardiovascular disease, hyperlipidemia, and some new evidence is showing us that those high fat intakes can have a negative effect on the gut microbiome, which is getting a lot of attention, due to its role in the development of Type 2 diabetes, as well as its management.

Finally, if we replace the carbohydrates with protein and fat, we’re going to get a very concentrated source of calories if portions are not managed well. And this could lead to increase in our weight, which is not one of the outcomes that we would like to have.

Some of the other diet plans that we see being talked about is the Mediterranean diet. There’s a lot of good evidence for this meal plan approach that’s beneficial for the prevention of Type 2 diabetes as well and for a possible prevention of gestational diabetes. This plan features a lot of fruits and vegetables, less red meat, healthy fat intake primarily from sources like olive oil. This has been well- studied in the literature, and there’s a lot of good evidence for this approach.

There’s also some other diets out there – the DASH diet, which is showing great evidence for long-term improved A1C and blood pressure control. This one is really focused on using less processed foods, more fruits and vegetables coming from those USDA recommendations, low saturated fat and trans-fat intake. And since many of our patients with diabetes have hypertension, this is often a good first approach.

Some other fad diets you probably have been wondering about are the intermittent fasting and Keto diets. It may help with some short-term weight loss, but the long-term safety has not been completely resolved, and it hasn’t been completely studied as far as a recommended approach for people with Type 2 diabetes. With fasting, of course, you run the risk of having possible hypoglycemic events occurring, and for those who are on insulin who are wanting to try the intermittent fasting approach, how does the clinician make the adjustments daily? That would be very hard for a clinician and a patient to communicate, “Well, today’s my fasting day,” or “Today’s my feasting day.” It would be very difficult to get that coordinated so that the medication and the meals are timed appropriately. And some of our extended basal pharmaceutical products would have to be eliminated for these people as a pharmaceutical option, if they have a cyclic fasting routine. That’s also true that if they’re going to take diabetes medications, and we all know we already struggle to get adherence on most of our medications now.

I think one of the other final lasting questions that we have about intermittent fasting diets and Keto diets is what effect does the fasting have on insulin resistance, which of course is a primary cause of Type 2 diabetes. You know, does the liver glycogenesis cycle get overstimulated? And what effect is it going to have long-term? And then finally, there is some new research being addressed with this type of approach – again, what effect does it have on the GI tract in terms of the gut microflora? We’re learning so much about the gut and how it relates to inflammation, and how it can be an important consideration in the treatment plan for the person with Type 2 diabetes that it’ll be interesting to see where that story turns out.

Dr. Anderson:
You know, it is interesting, I have had on at least two or three occasions, patients who’ve lost weight on the Keto diet, but their protein of choice is ground beef, bacon, sausage as opposed to turkey, fish, chicken. And I have seen LDL cholesterols go through the roof, even after losing 15 pounds on a Keto diet. So I think those of us in primary care need to pay attention to the possible downsides of some of these sort of radical diets.

Dr. Stanley:
Absolutely.

Dr. Anderson:
I’m Dr. John Anderson. To access this episode and others in this series, visit reachmd.com/DiabetesDiscourse, where you can Be Part of the Knowledge. Thanks for listening.