Variations of the high-fat diet have been popular for decades. Examples include the Atkins Low Carb Diet and numerous takes on the ketogenic diet. Although they are not uniform—there are vegan ketogenic diets, cyclical ketogenic diets, a diet that combines elements of the Mediterranean and ketogenic diets, and many more variations with differing levels of strictness—these diets are generally high in fat, high in protein, and low in carbohydrate.
Notice that I deliberately describe this as a high-fat diet. Although the preferred label low-carb diet may sound better, and it may be easier to market that concept, high-fat and low-carb are two sides of the same coin: to reduce the intake of carbohydrates to the level considered “healthy” in these diets, the proportion of fat in the diet must be high.
At CNS we have published a few articles on the ketogenic diet before. If you’re unfamiliar with those resources, I’d encourage you to check them out. Here are just a few of the most popular articles:
What is the Ketogenic Diet?
Is the Ketogenic Diet Natural for Humans?
Does the Ketogenic Diet Really Work for Weight Loss?
One aspect of the high-fat diet that we have not covered as much before are the difficulties many dieters face. In this article, we’re going to focus on five of the most common challenges.
I recently discovered a lifestyle and weight management center close to where I live—one affiliated with a very prestigious university, no less. When I saw that some of its doctors are well-known advocates for the ketogenic diet, my curiosity got the better of me.[1] I was soon on the website of one of those doctors, which I believe may provide a decent case study.
The first thing I noticed was the online shop.[2] Apparently, patients can find it difficult to snack. Too many snacks have carbohydrates, provoking a guilt response in the dieter. To meet this challenge, the good doctor “developed delicious guilt-free snacks to help make your low-carb lifestyle easier and more sustainable.”
Another thing that might help is a video on the doctor’s YouTube channel in which he walks you through the store—largely avoiding plant foods; speaking in defense of diet sodas, cheese crisps, eggs, and heavily processed meats (a Group I carcinogen according to the International Agency for Research on Cancer of the WHO[3]); and lamenting the lack of keto-friendly ice cream.[4]
I touched on this before: many versions of the keto diet exist. While they are all high in fat and low in carbohydrates, you might reasonably reach those targets by consuming very different foods. Likewise, the diet may be sold in various ways. In the YouTube video referenced above, the doctor illustrates this fact when inspecting several brands of “keto-friendly” ice creams and snack bars sold at his local grocery store. He dismisses many snacks for not being strict enough, preferring “that you eat real food” (which of course includes his own snack products).
If you’re looking for a more comprehensive list of foods that are allowed by this particular keto doctor, you’re going to have to pay for it.[5]
To help you navigate past all of this conflicting information, plus all the confusing research we might have heard about carbs, eggs, protein, whole grains, beans, and heavily processed meats, the doctor’s business also sells several courses. One of these focuses specifically on overcoming common obstacles to weight loss on a keto diet.[6] This is the course for keto dieters who are at risk of lapsing, and it brings us back to the central question of this article: Why would a person on a high-fat diet be at risk of lapsing?
The physical discomfort of the diet—which might in the short term include “headache, fatigue, nausea, dizziness, ‘brain fog,’ gastrointestinal discomfort, decreased energy, feeling faint, and heartbeat alterations,” a smattering of side effects that fall under the general umbrella term of “keto flu”—is only one component of what a keto dieter might feel.[7] There are also familiar emotional discomforts, which are conveniently listed in the sales pitch of the course mentioned above:
“You’re stuck . . . You’re doing everything right but the stubborn weight still won’t budge . . . You’re confused . . . You feel frustrated, disappointed, and demoralized . . . You’re overwhelmed . . . It’s disheartening to watch other people lose fat . . . You’re running out of hope that keto will ever work for you.”[8]
Tellingly, in the various descriptions of what the course includes, there are more than twenty direct references to weight or fat loss but not a single passing reference to health or wellness.
The average dieter may require six to twelve months to learn how to follow the ketogenic diet, but how many people will persist during and beyond that learning period? According to a researcher at Louisiana State University, six months is about as long as most people last on a diet, an amount of time that decreases significantly when the plan restricts entire food groups, as in the type of ketogenic diet proposed above.[9]
In a meta-analysis published in the Journal of Clinical Neurology, researchers looked at twelve studies involving adult patients with intractable epilepsy.[10] The meta-analysis evaluated 270 epileptic patients, comparing combined compliance rates for all types of the ketogenic diet, a classical ketogenic diet, and a modified Atkins diet. Because the efficacy of the diet is relatively high for controlling the symptoms experienced by epileptic patients, one might assume that these patients would be highly motivated to comply with the diet. However, even among such patients, the compliance rate for all types of the ketogenic diet was only 45 percent. That compliance is defined as following the diet “up to a given time point, usually the endpoint of each study.” In other words, more than half of these patients—which again, I presume were especially motivated by their condition—did not adhere to the diet for the entirety of their respective studies.
There were limitations to this meta-analysis. As the researchers point out in the discussion section, the total number of patients in the studies included was relatively small. Nevertheless, the findings are consistent with the concerted efforts of keto diet proponents to improve adherence. Another medical provider that specializes in using the keto diet to help patients lose weight at the lifestyle and weight management center referenced above conducts research on this topic specifically: improving the long-term adherence to the ketogenic diet.[11]
This very same doctor can be found on the medical review board of Diet Doctor, “the largest low-carb site in the world,” which offers paid subscriptions to struggling dieters. He also receives personal fees from Diet doctor, as disclosed in a conflict of interest statement in his adherence research.[12–14]
As you might expect, “extreme carbohydrate restriction can profoundly affect diet quality.”[7] Such a diet “may lack vitamins, minerals, fiber, and phytochemicals . . . are often low in thiamin, folate, vitamin A, vitamin E, vitamin B6, calcium, magnesium, iron, and potassium . . . Even when consuming only nutrient-dense foods, a 4:1 ketogenic diet is reported to have multiple micronutrient shortfalls.”
In a 2010 study of popular diet plans, researchers found the Atkins for Life diet plan deficient in the majority of essential micronutrients (fifteen of twenty-seven) as per the Reference Daily Intakes (RDIs) determined by the US Food and Drug Administration (FDA).[15] The researchers wanted to know how far off the diet was from providing sufficient levels of all those essential micronutrients. What they found is startling: “New calorie intakes were calculated and an evaluation determined that the Atkins for Life diet required 37,500 calories to become 100% RDI sufficient in all 27 essential micronutrients.”
How much food could a person eat before reaching 37,500 calories? Every year, competitive eaters from around the world arrive on Coney Island to see how many hot dogs and buns they can eat in ten minutes.[16][17] The competition has been televised on ESPN. The winner a few years ago was a man named Joey Chestnut (nicknamed Jaws), who at that time had won fifteen of the last sixteen competitions and who defended his title that year with a tally of sixty-three hot dogs and buns. The hot dog used for the competition (Nathan’s Famous) contains 150 calories, and the average bun is no more than around 150 calories.[18] That means Joey only ate around 18,900 calories. If he wanted to reach 37,500 calories, he would have to eat 125 hot dogs and buns. But of course, if on a ketogenic diet—“Hold the bun, please”—he would actually have to eat around 250 hot dogs.
Far be it from us to question Joey’s tenacity. The man is clearly in a class of his own. But at some point, even he would max out.
Because of the challenges described above, it’s difficult to ascertain just how impactful, either positively or negatively, this kind of diet is on long-term health. What we do know is that there are risks associated with consuming high levels of foods containing animal protein[19–22] and risks associated with yo-yo dieting, which results in rapid weight fluctuation and increased mortality.[23]
Finally, it’s worth mentioning that many of the broader trends that make adherence to a high-fat diet difficult also apply to other diets. Dieters of all types can and do face similar challenges. I believe this might have something to do with expectations and the goals motivating the average dieter. It’s obvious from reading about the ketogenic diet and other dieting plans that weight loss is the be-all and end-all for many people. As I alluded to before, there is much less focus on overall health—including emotional health—than on fat loss. And though losing weight is often going to help improve overall health, focusing on weight loss instead of wellness may often be counterproductive. It may even perpetuate many unhealthy eating patterns.
Depressive symptoms are associated with a higher rate of obesity.[24] Moreover, many individuals experience psychological distress “if they have tried to lose weight in the past and failed to achieve their desired weight.”[25] This is a very dangerous dynamic. A person pinning their hopes on a highly restrictive, nutrient-deficient diet that is difficult to adhere to is often going to fall into this vicious trap of feeling like a failure, not because they are a failure but because the diet’s exploitative salespeople are aggressively marketing products and ideas that fail to sustainably promote health in the long term.
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