The ketogenic (keto) diet has become increasingly popular in recent years, with Google searches for the word “ketogenic” increasing almost 10 times in the last several years.
However, the diet is highly controversial and there are two sides of the camp: Physicians, specialists, and followers of the diet who purport it can completely reverse Type 2 diabetes, and doctors, diabetes experts, and nutritionists that believe it’s a dangerous and unsustainable fad.
dLife speaks with a registered dietitian nutritionist, Rosslyn Cary, MS, RDN, and Holly Hackman, RD, CDE, a clinical dietitian and certified diabetes educator based at MemorialCare in Long Beach, Calif. for their take on the keto diet, and specifically what it means for someone with diabetes.
The Keto diet is popular. What are your thoughts about this diet?
“The keto diet and very low carb diets have been popular in recent years but it’s important to point out that these are fad diets and are not healthy in any way,” says Hackman.
Hackman explains that people will lose weight when on this diet, but once they stop the diet, they will gain the weight right back.
“Most of the initial weight that is lost is water weight, so it isn’t really true weight loss and can actually lead to dehydration if you aren’t careful,” warns Hackman. “While the reversal of Type 2 diabetes is possible with weight loss, it is not necessarily due to the keto diet itself and not every person will have this result.”
Hackman says having blood glucose reach normal levels also does not mean diabetes will be reversed forever and people should be monitored by their physicians.
“You also need to keep the weight off in order to remain off diabetes medications,” Hackman says. “People with Type 2 diabetes would be better off making healthy lifestyle changes that they can continue for life instead of following a fad diet that may help them lose weight but is extremely hard to follow.”
She says it’s important to keep in mind that most physicians are not thoroughly educated in nutrition so even though some physicians may promote it to lose weight, the long term effects have not been seen yet and they may change their minds in the future.
“New studies have been showing high-fat diets can lead to insulin resistance and can increase the risk of developing Type 2 diabetes, but more research is needed,” says Hackman.
How often do you see patients on a keto or very low carb diet?
Hackman personally doesn’t see patients that are following the keto diet for counseling or help with their diet, especially since she does not promote the keto diet.
“We do see patients that are hospitalized for things related to following the keto diet since the diet has become more popular — we are seeing a few patients a month at least,” Hackman acknowledges.
While there is no real research to show these patients were definitely hospitalized due to the keto diet, the diet itself can lead to the conditions they were admitted for, she explains.
Some of the complications include severely elevated cholesterol and triglycerides leading to acute pancreatitis, gallstones, constipation, electrolyte abnormalities, rhabdomyolysis, dehydration, acute kidney injury, and end-stage renal disease leading to dialysis rapidly after starting the keto diet.
“Since people with diabetes are already at an increased risk of developing kidney disease, it seems to accelerate kidney damage due to high levels of nitrogen excretion so if a person has even mildly decreased kidney function, they should not try the keto diet or a very low carb diet,” Hackman advises.
“I have already seen at least 3 patients with diabetes and mild kidney disease prior to starting the keto diet to end-stage renal disease that are now on dialysis within a matter of months,” she says.
Hackman says her team also saw a patient that had followed the keto diet for 2 years have a quadruple cardiac bypass.
“It is rare to find a person that has followed the diet for that long, but it most likely accelerated his heart disease,” Hackman says. “Anyone with familial hypercholesterolemia or hypertriglyceridemia should not try the keto diet.”
Following the keto diet can also harm gut health and decrease the number of beneficial bacteria in your digestive tract due to a lack of fiber.
Constipation is a frequent side effect of the keto and very low carb diets.
For this reason, Cary says they have also seen a handful of patients admitted with bowel obstruction who were following the ketogenic diet.
How can the keto diet affect your body?
Another problem with the keto or low carb diet is there are not many studies which look at the effects this diet over the long term.
Possible long term effects are kidney stones, weak bones, and bone fractures from being in chronic acidosis increased dyslipidemia and cardiovascular disease, and an increase in muscle loss.
“The preferred fuel source for your brain is glucose,” says Hackman. “If you aren’t eating any source of carbohydrate to produce glucose, your body will break down your glycogen stores.”
After 24 hours, Hackman explains your stores will be depleted and muscle is broken down to form glucose for your brain since the brain does not prefer to use ketones for fuel.
Diets low in fiber (fruits, vegetables, beans, and whole grains) have also been shown to increase the risk of colon cancer says Hackman.
She also says that most antioxidants come from these healthy carbohydrate sources.
Cary agrees with Hackman on the dangers of not getting enough fiber, which can lead to other complications.
She also points out that following any restrictive diet such as keto can also be very isolating around social situations which may lead to disordered eating patterns, unhealthy relationship with food or increase the risk of developing an eating disorder.
How do medications need to be adjusted when someone adopts a ketogenic diet?
“Anyone taking medications for diabetes should talk to their healthcare provider prior to starting a low carb or keto diet,” says Hackman.
Because the keto diet increases the risk of hypoglycemia for anyone on insulin, medications would need to be adjusted prior to starting this diet.
Medications that can cause hypoglycemia will need to be stopped or adjusted, this includes Sulfonylureas, Meglitinides, and meal insulins.
It is also recommended that basal insulin is decreased as well but will need to be individualized for each person.
Since keto diets can lead to dehydration due to increased water loss, people on diuretics may need these medications adjusted as well.
“It is imperative that anyone following a keto diet with diabetes routinely follow up with their doctor and dietitian to adjust their medications and attempt to meet their nutrient needs,” Cary advises.
How should people on a keto diet monitor their blood sugars? Are most patients using CGMs now?
According to Hackman and Cary, it’s most likely that people with diabetes on the keto diet will need to monitor their blood glucose even more often to make sure they aren’t having an increase in hypoglycemic events.
They will also need to check their urine for ketones on a daily basis.
“A continuous glucose monitor would be a huge benefit for someone following a keto diet,” Hackman says, “I would recommend using a CGM for any Type 1 trying it.”
She notes CGMs are definitely utilized more often these days by people with diabetes, but the majority are T1D and T2D using insulin.
Do you not recommend the keto diet for people with diabetes?
“I personally don’t recommend this diet to anyone with or without diabetes,” says Hackman. “It is just not a healthy diet and long term effects are not known yet.”
Cary indicates that research suggesting improvements for diabetes is very limited and usually involves small sample sizes.
For both Hackman and Cary, a diet that cuts out most fruits and vegetables is enough for them to not recommend the diet to anyone.
Instead, they believe individuals would be better off following a Mediterranean diet to improve their overall health.
The nutrition and diabetes expert believe the keto diet is not a miraculous new diet that will cure diabetes and give you a slim and trim body, but rather, can create new medical problems and for most people is not worth the risk.
“It is also very inconvenient and hard to follow if you have a social life,” says Hackman. “Just because the diet worked for a friend or celebrity and they lost weight, it does not mean everyone should do it.”
Both Hackman and Cary believe making lifestyle changes by eating more nutrient-dense foods like fruits, vegetables, beans, legumes, and whole grains is the better way to go.
They also support cutting down on high calorie, nutrient lacking foods and increasing physical activity that will benefit people, with or without diabetes, for the rest of their life.