The Skinny on the Keto Diet

“the keto diet is a low carb, high fat diet to shift the body’s metabolism away from carbs and toward fat and ketones.”

-Healthline

The Keto Diet is easily one of the most common trends I get questions and comments about. I attempted to do the keto diet myself, actually, back in 2018. But as with any fad diet trend I convince myself to try, I didn't stick with it long. However, it did encourage me to do research into it and figure out what the hype was all about, as well as the not-so-shiny aspects of the eating plan that most advocates don’t seem to like to mention. In my opinion, there is no one "perfect diet," because for every positive, there is usually a negative — but this is true for some diets more so than others.

The keto diet was developed for pediatric patients with epilepsy by Dr. Russel Wilder in 1921 in which fat made up 90% of an individual’s caloric intake. By restricting carbohydrate consumption and allowing the body to deplete its glycogen stores, the body turns to its second in command to meet energy demands: fat. Fat cells go through gluconeogenesis (the formation of glucose from non-carb sources) which results in ketone bodies, putting the body in a state of ketosis. Those ketone bodies, however, can be converted back into Acetyl-CoA which allows for even more metabolic processes to occur. Science! I love it.

Fat produces more energy for the body than carbs do, but because the process of going through ketogenesis, gluconeogenesis, and beta-oxidation is longer, more in-depth, and requires more energy, it’s not our body’s primary fuel source. In short, our bodies want to take the simplest route possible. Using fat as a fuel source, even though it produces more energy in the long run, is not the simplest route; glucose is. So, by consuming as few carbs as possible, we decrease the availability of glucose and ultimately end up forcing the body to create new glucose molecules from stored fat.

There are a lot of success stories from people who have maintained discipline while on the keto diet — the science behind it is sound. But, as with any diet, no matter how simple, healthy, or well-intentioned they may be, the keto diet has a list of pros & cons that should be taken into consideration.  I’m going to compare & contrast the various arguments for/against the keto diet as objectively as possible. This is not going to be an opinion piece. I did my best to find credible online sources to reflect all sides. Regardless, you should consult with your doctor or a dietitian before starting any diet plan.

Note that in scientific studies, especially surrounding nutrition, there are limitations that present challenges in terms of being able to apply the findings to the general population. The discussion surrounding the keto diet is still one that requires additional research in order to come to an ultimate conclusion. So far, there are plenty of small studies that can support the short-term benefits of the keto diet, but the sustainability of the diet is still in question and requires further discussion.

---

Weight loss

Let’s start with the primary reason most people are attracted to this diet: weight loss. I would go as far as saying that the effects the keto diet has on weight is undeniable; I’ve seen some really incredible transformations. Scientifically, research studies go back and forth on whether it has more to do with possible portion control rather than the macronutrient composition, but I think when it comes down to it, the science of metabolism is pretty straight forward as this result goes.

Cardiovascular system

Some studies have shown positive effects of the diet on HDL cholesterol, blood pressure, triglyceride levels, glycemia, insulin, and C-reactive protein — but these findings were only significant up until the 6 month mark; statistical significance of outcomes decreased between 12-24 months. While there are some benefits, there are also risks associated with its impact on heart health: LDL and total cholesterol levels are increased in those following the low-carb diet which may increase risk of developing atherosclerosis. However, it’s important to consider the quality of the food ingested — an NIH study states that “mortality was worse when fat and protein sources were animal-derived instead of plant-based.” The popularized version of the keto diet advertises consumption of large amounts of potentially low-quality fats from meat, dairy, cheese, and processed/salty foods, and rarely focuses on unsaturated, plant-based fat sources like vegetables, nuts, and whole grains. Not to mention that by avoiding carbs, most keto diet participants aren’t getting sufficient (if any) amounts of fiber; a nutrient which helps regulate LDL cholesterol levels.

Hormones & Metabolism

There has been some evidence that the keto diet can positively impact women struggling with polycystic ovarian syndrome (symptoms include irregular periods, infertility, obesity, and effects of hyperandrogenism). Small, short-term studies have shown a significant decreases in serum insulin, free testosterone, and LH-to-FH ratio — but some of these observations were not significantly impacted by week 12 of the study. As with everything else mentioned so far, more research is needed to make a definite correlation.

Alisa Vitti, author of In the FLO points out a few things, as well:

• Animal protein heavy diets can lead to liver congestion, and therefore estrogen dominance

• Women practicing the keto diet should avoid intentionally restricting calories or being too strict

• Some research suggests that it could affect T3 production

In terms of metabolism, while the diet has had some positive impacts on insulin and hemoglobin levels in some study participants, the keto diet is not recommended for individuals with Type 1 Diabetes due to the possibility of ketoacidosis and/or increase risk of hypoglycemic incidents. Some studies have indicated the possibility of the keto diet to normalize hemoglobin A1C levels and glycemic variability, but individuals with diabetes should not start the keto diet without first consulting a healthcare professional.

---

These have been the primary statements regarding the keto diet’s positive effects on the body. The overall theme, though, is that there is still a lot more research that needs to be done before any conclusions about its safety and effectiveness can be solidified. The only thing I will state as my “opinion” on the topic is this: yes, weight loss will happen because the science behind it is valid. However, a lot of the benefits regarding heart health and hormone regulation can really be attributed from weight loss in general, not just weight loss specifically from the keto diet. Weight loss of just 5-10% of your current body weight has been shown to have incredible effects on your health. Studies still struggle to verify the extent to which this diet can be sustained. The diet would likely have a more positive rating from scientists and nutritionists if it was centered around healthier, plant-based sources of fat — but even just searching “keto recipes” on Pinterest pulls up meals primarily focused on cheese, butter, bacon, and other forms of animal-based, saturated fats that can potentially increase risk of other health issues down the line. Not to mention that if an individual were to go back to standard diet, it’s possible that the desired outcomes of the keto diet will be reversed — this concern might keep people on the keto diet for longer periods of time. The issue here is that science has yet to determine the safety of prolonged or indefinite use. Claims against the consumption of carbs should always be researched because often times, they will be referencing refined carbohydrates which all healthcare and fitness professionals agree on the disadvantages of.

Summary

Benefits

• Weight loss

• Hormone regulation

• Increased HDL cholesterol, and possible decrease in LDL & total cholesterol depending on diet quality

• Possible neuroprotective benefits

Risks

• Kidney stones (from increased animal fat & protein consumption; can increase uric acid, protein, and calcium levels in the blood)

• Mineral & vitamin deficiencies, which can impact bone density

• Buildup of fat in the liver

• Increased LDL & total cholesterol, leading to increased risk of atherosclerotic properties

• “Keto flu” symptoms as body adjusts to changes in dietary patterns

Individuals that should avoid the keto diet

• Diabetics (especially insulin-dependent, or those on SGLT2 inhibitors)

• Those with history of eating disorders

• Those with kidney disease or pancreatitis

• Pregnant or breastfeeding women

Takeaway

As with any diet plan, consult with your doctor before starting and proceed with caution. Doing your own research is critical, but make sure to pull from unbiased and/or trustworthy sources. It's easy to let social media or pop culture highlight the positives without always providing the disclaimers that come alongside it. And, as always, remember that our genes and microbiomes are unique, which means one (diet) size does not fit all.

SOURCES

• https://www.medicalnewstoday.com/articles/319196#risks-and-complications

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7480775/

• https://www.health.harvard.edu/blog/ketogenic-diet-is-the-ultimate-low-carb-diet-good-for-you-2017072712089

• https://academic.oup.com/jn/article/150/10/2835/5921004

• https://academic.oup.com/jn/article/150/6/1354/5673196