Should you recommend keto to your clients?

Highlights:

• The ketogenic diet is an effective way to lose weight and manage diabetes
• The ketogenic diet may be able to extend lifespan by affecting the mTOR signaling pathway
• The ketogenic diet has several problems, the main being long-term adherence 

Ketogenic diet 

The ketogenic diet (often called keto) has gained a substantial amount of popularity in recent years. Previously, it was primarily used to treat epilepsy. Nowadays, a lot of people find it very effective for weight loss. Switching to burning mainly ketones for energy has a wide array of effects on the human body. It seems to help with diabetes, neurodegenerative disease, and possibly even with longevity. But, there are also concerns about adherence and nutritional adequacy of this approach to nutrition. In this article, we will explore the benefits and downsides of going keto.

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What does it mean to go keto?

The ketogenic diet can be characterized as a very low carbohydrate diet that is moderate in protein and high in fat. This reduction in carbohydrates puts the body into a metabolic state called ketosis. In ketosis, the body uses fat to produce ketones which become the main energy source in times of low carbohydrate availability. The ketogenic diet typically limits daily carbohydrate intake to 50 g to achieve ketosis. This carbohydrate threshold is different for everyone, and ketosis can be reached by other means such as fasting or prolonged exercise. In general, the ketogenic diet fits in the following macronutrient split:

• Carbohydrates 5-10%
• Fat 60-80%
• Protein 15-35%

In the 1920s, the ketogenic diet was introduced as medical nutrition therapy for epilepsy. Its use has diminished as modern anticonvulsants became available, but it remains an effective treatment for drug-resistant epilepsy until today (1). Keto saw a resurgence in the 1970s when the Atkins diet became popular for its weight loss benefits. Atkins is also a type of low carbohydrate diet that makes use of ketosis. Recent research suggests that keto might have other benefits beyond epilepsy and weight management, but there are issues that we need to keep in mind.

Weight loss

One of the main draws of the ketogenic diet is weight loss. A large meta-analysis of 14 studies confirmed that ketogenic diets were effective in improving metabolic parameters associated with blood sugar control and weight in patients with overweight or obesity, especially those with preexisting diabetes. The selected studies lasted between 4 weeks and 12 months and included 734 participants with overweight or obesity, including 444 diabetic patients and 290 non-diabetic patients. The mean difference in weight changes between keto and comparator diets was −7,78 kg in diabetic patients and −3,81 kg in all patients (2). However, a later meta-analysis found that very low carbohydrate diets showed a similar amount of weight loss to low-fat diets, so they don’t stand out as better than other diets in terms of weight loss. Researchers also noted that adherence is likely poor for very low carbohydrate diets without intensive support from health professionals. They also warned that intake of saturated fat should be monitored to ensure recommended intakes (3).

Diabetes

In recent years, the American Diabetes Association, as well as several institutions from other countries, endorsed low carbohydrate diets as a treatment option for type 2 diabetes. It was a result of mounting evidence in favor of these diets. The research for very low carbohydrate diets such as keto showed efficacy as well. A meta-analysis showed keto controls glycemia and decreases body weight for up to 6 months in people with obesity and diabetes. It also showed that reductions in antidiabetic medications continued until 12 months on a diet. Researchers warned that a major limitation of very low carbohydrate diets is patients' lack of adherence (4). Another meta-analysis showed that following a low carbohydrate diet for 6 months can lead to remission of diabetes. It also said that a subgroup of very low carbohydrate diets was less effective than other less restrictive low carbohydrate diets due to differences in adherence (5).

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Neurodegenerative disease

Ketones can replace glucose as the majority energy source in the brain when the body enters ketosis. It is at the core of why the keto diet helps treat epilepsy and also why research suggests it might play a role in the treatment of neurodegenerative disease. Even though this research is still in the early stages, a systematic review of randomized controlled trials concluded that ketogenic therapy looks promising in improving both acute and long-term cognition among patients with Alzheimer’s disease and mild cognitive impairment (6).

Keto and longevity

The above-mentioned benefits of keto, such as weight loss, diabetes management, and improvements in cognition of Alzheimer’s disease patients, all contribute to longevity. Research shows that keto might be connected to longevity in a more direct way. A study looked at what happens to the lifespan of rats when their feed shifts from high carbohydrate (only 13% of calories from fat) to high fat (89% of calories from fat). The researchers found that mice on the ketogenic, high-fat diet lived longer; their median lifespan was 13,6 % higher than the control group. The study also showed that motor function, memory, and muscle mass were well preserved in ketogenic mice as they aged (7). Translated to humans, this would equate to something like 10 more good years.

It is still unclear how exactly the ketogenic diet improves longevity. One of the most compelling theories says that carbohydrate restriction and protein moderation inhibits the mTOR pathway. The mTOR pathway regulates gene transcription and protein synthesis to regulate cell proliferation and immune cell differentiation. Inhibiting this pathway causes the body to prioritize repair instead of growth. This is certainly beneficial for longevity, and keto achieves both.

Issues with the ketogenic diet

Unfortunately, the ketogenic diet is not without its flaws, and the chief among them is adherence. For the keto diet to work properly, the severe carbohydrate restriction needs to be respected at all times. There is no space for cheat meals, sweets, or holiday exceptions because a single high carbohydrate dish could cause the body to get out of ketosis. This includes alcoholic beverages and soft drinks. High-carbohydrate ingredients such as potatoes, rice, corn, or wheat are staples in almost every cuisine around the world. Overall, this makes keto a very socially isolating diet that is hard to stick to. This is evidenced by high participant dropout rates in many ketogenic diet studies (8).

Following a keto diet poses several other issues even when adhered to properly. Elimination of carbohydrate-rich foods typically introduces a higher proportion of animal-based foods and opens the possibility of nutritional deficiencies. Here are the most notable concerns on a ketogenic diet.

• Higher than recommended saturated fat intake. Studies show that the keto diet may increase LDL (bad) cholesterol and cardiovascular risks (8).
• Risk for ketoacidosis. People taking sodium-glucose cotransporter 2 (SGLT2) inhibitors as treatment for type 2 diabetes should avoid keto because they would be at an increased risk of developing life-threatening ketoacidosis (9).
• Alterations of the gut microbiome. Very low carbohydrate diets tend to lack fiber which may negatively affect the gut bacteria. Research on the topics shows mixed results (10).
• Nutrient deficiencies. Studies suggest that clinicians who manage people on calorie-restricted keto diets should recommend supplementing with potassium, sodium, magnesium, calcium, omega-3 fatty acids, psyllium fiber, and vitamins B, C, and E (11). The dosage should be decided based on dietary reference intakes, the composition of the ketogenic diet, and blood tests. 

These short-term effects of the ketogenic diet are well reported and established. However, the long-term effects are not yet well understood. We are still missing robust data about the health implications of being keto for decades.

Practical recommendations

Some of the downsides of going keto can be mitigated by proper education, supplementation, and correct food choices. Here are several practical recommendations that you can offer to clients that are interested in the ketogenic diet.

• Informing clients about the expected side effects when switching to keto known as the “keto flu”. Increased intake of salt and fluids in the first week helps.
• Reducing saturated fat intake. Replace some animal protein sources with plant protein powders such as soy, pea, or hemp protein powder and increase unsaturated fat sources such as avocados, olives, nuts, and seeds.
• For weight loss keto diets that restrict calories suggest supplementing B vitamins, vitamin C and E, potassium, sodium, magnesium, calcium, and omega-3 fatty acids.
• Implementing fermented food and beverages such as yogurt, kefir, or kimchi and supplementing with prebiotics and probiotics to improve the microbiome.
• Adjusting fiber intake in case of constipation. High fat intake might cause diarrhea after switching to keto; reduced portion size and increased meal frequency can help.
• Focusing on sufficient omega-3 fatty acid intake with sources such as fish, seafood, walnuts, or flaxseed.
• Reducing intake of processed foods such as keto cookies, keto pizza, etc.
• Offer tips for whole-food keto snacks such as hard-boiled eggs, beef jerky, guacamole, nuts, seeds, and olives.

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Conclusion

The ketogenic diet can be used as a short-term strategy for weight loss and as a treatment for type 2 diabetes. It can also be the only option for people with drug-resistant epilepsy. In these scenarios, nutritionists should work closely with patients to help them avoid nutritional deficiencies and improve adherence. The keto diet is showing promise as a longevity tool in animal studies. Still, there is currently not enough research to recommend it as a long-term strategy for longevity in humans.

References

1. Ułamek-Kozioł M, Czuczwar SJ, Januszewski S, Pluta R. Ketogenic Diet and Epilepsy. Nutrients 2019;11(10):E2510. 10.3390/nu11102510
2. Choi, Yeo Jin et al. "Impact of a Ketogenic Diet on Metabolic Parameters in Patients with Obesity or Overweight and with or without Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials." Nutrients vol. 12,7 (2020): E2005.
3. Ross, Lynda J et al. "Exploring the highs and lows of very low carbohydrate high fat diets on weight loss and diabetes- and cardiovascular disease-related risk markers: A systematic review." Nutrition & dietetics: the journal of the Dietitians Association of Australia vol. 78,1 (2021): 41-56.
4. Rafiullah, Mohamed et al. "Effect of a very low-carbohydrate ketogenic diet vs recommended diets in patients with type 2 diabetes: a meta-analysis." Nutrition reviews vol. 80,3 (2022): 488-502.
5. Goldenberg, Joshua Z et al. "Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data." BMJ (Clinical research ed.) vol. 372 (2021): m4743.
6. Grammatikopoulou, Maria G et al. "To Keto or Not to Keto? A Systematic Review of Randomized Controlled Trials Assessing the Effects of Ketogenic Therapy on Alzheimer Disease." Advances in nutrition (Bethesda, Md.) vol. 11,6 (2020): 1583-602.
7. Roberts, Megan N et al. "A Ketogenic Diet Extends Longevity and Healthspan in Adult Mice." Cell metabolism vol. 26,3 (2017): 539-546.e5.
8. Batch, Jennifer T et al. "Advantages and Disadvantages of the Ketogenic Diet: A Review Article." Cureus vol. 12,8 (2020): e9639.
9. Qiu, Hongyu et al. "Ketosis and diabetic ketoacidosis in response to SGLT2 inhibitors: Basic mechanisms and therapeutic perspectives." Diabetes/metabolism research and reviews vol. 33,5 (2017)
10. Paoli, Antonio et al. "Ketogenic Diet and Microbiota: Friends or Enemies." Genes vol. 10,7 (2019): E534.
11. Muscogiuri, Giovanna et al. "The management of very low-calorie ketogenic diet in obesity outpatient clinic: a practical guide." Journal of translational medicine vol. 17,1 (2019): 356.

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