Low-Fat, Keto, or Somewhere In Between?

When it comes to the consumption of dietary fat, there are a lot of varying opinions.  Eating a low-fat diet has been mainstream since the 70’s, but in recent years the ketogenic diet (which advocates that 70-80% of total caloric consumption come from fat) has gained popularity.  The problem is that this leaves most people confused as to whether dietary fat is good or bad.  And the short answer is that fat is good. The complete demonization and elimination of any single macronutrient, whether fat, protein, or carbs, will be to the detriment of our health. 

When it comes to dietary fat, the question is not about whether you should or shouldn’t consume it.  The question is about how much fat a person should consume, particularly relative to protein and carbs.  And that is what we are going to get into. 

Fat’s “Criminal History” 

It’s important to understand a little bit about where the stigma that “fat is bad for you” came from.  The name of this particular macronutrient is associated with something we generally view as negative: fat.  However, the low-fat recommendations that were widely accepted for decades started largely due to a study called the “Seven Countries Study” conducted by Ancel Keys (https://www.sevencountriesstudy.com/).  This study proposed that there was a correlation between consumption of dietary fat (particularly saturated fat) and cardiovascular disease.  This was done by pointing out that seven countries with high rates of cardiovascular disease also have typical diets that are high in dietary fat. 

Without going too far into the details, it was later discovered that Keys' study was not as conclusive as it originally seemed.  It seems as though Keys selected only countries that would prove his hypothesis, and he was accused of intentionally leaving out countries, such as France, that had historically low rates of cardiovascular disease while consuming a diet high in saturated fat. 

All that to say, many people in the past 50 years have followed the guidelines for a low-fat diet as a result of this study, which grossly misrepresented the relationship between dietary fat and cardiovascular disease.  And it has only been in recent years that the trend is starting to be reversed. 

So That Means We Should Go Keto? 

If a low-fat diet is not the way to go, it doesn’t mean that we should swing the pendulum to the other end of the spectrum.  The ketogenic diet recommends 70-80% of total caloric intake come from dietary fat, while only 5-10% of calories come from carbs, and 10-20% of calories come from protein. 

First of all, it needs to be said that the above macronutrient ratios are very specific.  And “going keto” is not as simple as cutting out carbs and eating as much bacon as you want. 

Second, “low-fat = bad, so high-fat = good” is taking something very complex (the human body) and looking at it simplistically.  If you’re wondering whether or not you should follow the ketogenic diet, the short answer is “probably not.”  But it’s also important to understand the history of the ketogenic diet and the scenarios in which it is effective before you make that decision. 

What most people don’t realize is that the ketogenic diet was initially used as a way to help treat cancer patients.  Because sugars feed cancerous cells, consumption of lots of fat with very little carbs will force the body to use dietary fat as an energy source, thus stalling the growth of cancerous tissue by way of cutting off its food source. 

As a general rule, the ketogenic diet is helpful in aiding the treatment of cancer patients.  It also has applications for addressing diabetes and blood sugar related issues.  And it can even work well for very sedentary people that are otherwise healthy.  However, it is not generally recommended that healthy, active people follow a ketogenic diet.  Whether your goals are related to improving your body composition, or physical/athletic performance, there is likely a better way to go. 

15-40% of Total Caloric Intake 

Before providing some guidelines about the appropriate amount of fat consumption, I need to make sure I mention that nutrition is highly individualized.  And what I’m about to share are general guidelines. 

Each gram of dietary fat contains 9 calories of energy, whereas protein and carbs each have 4 calories per gram. That means it is both a valuable source of fuel, as well as an easy place to cut calories to lose weight/bodyfat. But it is imperative that we do NOT attempt to follow a “no-fat” diet. To completely remove dietary fat from our nutrition is extremely detrimental to our health.  We need fat to help construct the membrane of our cells, cushion our organs, produce hormones, absorb fat-soluble vitamins, and much more. A reduction in fat can be beneficial, but there should always be a portion of our nutrition that comes from fat. 

So, when it comes to figuring out what percentage of your total caloric intake should come from dietary fat, the general recommendation is between 15-40% of total caloric intake.  Obviously, that is a wide range, so when deciding which end of that range you should be on, I recommend this guideline: 

The lower end of the range should be used only when dieting to lose body fat and only for individuals that are training hard and are already relatively lean.  If the goal is to maintain body composition, gain muscle mass, or improve strength, or if the individual is overweight and/or has a low activity level, then fat consumption in the 30-40% range is preferable. 

The most important aspect of a successful fat loss program is a caloric deficit.  This means that total energy consumption must be reduced.  The reason that individuals that are already lean and/or follow an intense training regimen should reduce fat and attempt to keep carbohydrate intake high is due to the fact that carbs are more readily available for the body to use as energy, and there are not sufficient stores of fat tissue to draw from to cover the energy imbalance. 

However, when the goals change, so do the nutritional requirements.  When the goal is maintenance of body composition, an increase in lean mass, or improvements in strength, then a caloric deficit is not necessary.  This means there is no energy imbalance, and we will be able to use a blend of fats and carbs to cover the body’s energy needs. Thus, it’s totally fine to allow fat consumption to go up to the higher end of the range.  Similarly, those that are overweight or have high amounts of adipose/fat tissue, do not need to maintain a high carbohydrate intake. They can also consume fats at the higher end of the range, provided that total caloric intake is managed. 

Conclusion 

As I mentioned, nutrition is very individualized, and it’s particularly complicated when trying to lose body fat. Hopefully the information and guidelines provided here will give you a good starting point. And if you are trying to lose weight/fat, please be sure and check out our Fat Loss Nutrition Calculator (https://starklife.us/fat-loss-calculator/)to help get an idea of what your nutrition should look like!