Breaking down the facts on two popular low carb trends and what it means for you.

With the current mainstream popularity of low carb diets, it is important to stay informed on what these dietary lifestyles are all about. Let’s break down the facts on two popular low carb trends and what it means for you.


Both Paleo and ketogenic diets are synonymous with low-carb dieting.  Paleo is a low-carb diet which is said to mimic how people in the Paleolithic era ate, calling for the elimination of grains, legumes, dairy, and all processed foods.  One of the main benefits of following a Paleo diet is that it promotes eating a more plant-based diet of fruits and vegetables while lowering the intake of foods loaded with added sugar.

The ketogenic (or keto) diet is more restrictive and aimed at reaching the state of ketosis, a metabolic state in which ketones are used as the primary source of energy as opposed to glucose. In order to reach and maintain ketosis, one must follow a diet very high in fat, low in all carbohydrate (including fruit), and also low in protein.  Keto also restricts empty calorie foods high in sugar and has actually been used in the clinical setting for treatment of epilepsy given its effect on reducing seizures.  


While both diet lifestyles have gained avid followers in recent years, there is no significant research evidence that supports either of these diets can outperform diets which supply the recommended amount of carbohydrate in those who are active. Similarly, regarding weight loss, these diets have shown no advantage when compared to non-carbohydrate restricted diets with equal caloric intakes. In fact, no diet out there has the abundance of research correlated with reduced cancer risk, heart disease, and diabetes, other than those which include a balanced consumption of fruits, vegetables, and whole grains.


Some who argue in favor of low carb diets may reference tribes such as Inuit, Masai, and Tokelau, who didn’t have much access to carbohydrate containing foods. Do you need vast amounts of carbohydrate to survive? The answer is a simple “no.”

However, if you are planning to run a marathon, deadlift 500lbs, or have what most would consider a normal social life, then you may want to reconsider fixing your relationship with carbs. On a side note, Okinawans have a rather high consumption of nutrient-dense carbohydrates, yet are leaner and live longer on average when compared to other societies.


Your requirement for carbohydrates is highly dependent on daily activity level, so let’s consider the facts of fueling requirements. Athletes require more carbohydrate energy whereas sedentary individuals need less. For sedentary days, only 1 to 3g per kg of body weight may be necessary.

As you become more active, your needs will increase depending on the type of exercise and level of intensity.  For example, a powerlifter may require up 6g/kg, whereas an endurance athlete needs a minimum of 8g/kg.  In the case of a male powerlifter weighing 185 lbs, this would be equivalent to 505g of carbs, or 2018 calories, that they need to consume. If the powerlifter followed a Paleo diet, roughly 17 bananas or other pieces of fruit (approximately 30g of carbs per piece) is required to meet his needs. In comparison, a cup of rice or other starch contains approximately 45g of carbohydrate.


For low-carb enthusiasts who lead an active lifestyle, it’s highly recommended to work closely with a nutrition professional or dietitian to ensure you’re not wasting away all that precious muscle you’ve worked so hard to build, nor selling yourself short on energy for endurance events. For example, many people who attempt to follow the keto diet are under the impression  that it is a high-fat/low-carb diet. However, in order to reach full ketosis, you must also eat relatively low protein as well because it is likely to be converted to glucose, thus taking you out of ketosis. Classic keto requires at least 3g of fat for every 1g of carbohydrate and protein; this equates to about 75% of total calories from fat with the remaining 25% divided between carb and protein. This is not to be confused with modified Atkins, which is less restrictive of protein.

Often times, restricting fruit intake is not advised given their abundance in vitamins, minerals, and antioxidants. For the purpose of keto diets, one would need to restrict their fruit intake, whereas those on Paleo diets can eat bananas to their heart’s content. Because fat will be the main source of energy in keto, one would need to focus on nutrient dense food like nuts, seeds, and heart healthy oils such as olive and avocado. These fats are still shown in the research to be more beneficial than diets higher in saturated fat (e.g. animal fat, butter, full fat dairy, and tropical oils).  All Paleo/Primal and keto diets recommend removing grains and focusing primarily on vegetables for fiber.   In general, most vegetables contain very low carbohydrate, and the only Paleo-approved higher carb-containing foods are root vegetables, such as sweet potato.

The issue with most low-carb diet is similar with most other fad diets. It’s too restrictive, and therefore not very sustainable for most. Many times, I will ask a client who is considering going low-carb: do you believe you could go the rest of your life without pizza? If not, then it’s probably not the best diet for you.

Think about the next time you’re on the road, getting cranky, and your only option for food is a gas station with nothing but food that comes out of a package. Or it’s one of your favorite holidays and you know darn well you’re not passing up on Grandma’s homemade cookies that are going to send you skyrocketing out of ketosis. Sure, perhaps with dedication we can restrict ourselves for a month or two, but remember that your best health is what you can sustain for a lifetime.

Believe me, there’s a way to fit all foods on your plate and still be “fit.”

Nick Biase, RDN is a San Diego-based registered dietitian nutritionist specializing in sports nutrition and wellness. Nick is a Marine veteran, fitness enthusiast, home brewer, and a firm believer that you can keep both 6-packs. Develop your nutrition game plan with Nick, make a visit to Nutrition Cadre.

  1. 3g of fat per 1g of protein or carbs doesn’t make 75% of calories from fat and 25% of calories from protein and carbs….cause 1g of fat is 9 calories,where as 1g of protein or carbohydrate is 4 calories…

    1. You are correct, fat is 9 calories per gram while carbohydrate and protein are 4 calories per gram. However, the keto diet as explained in the article refers to carb and protein being split among those calories; 3g fat to 0.5g carbohydrate and 0.5g protein. For example, following a 2000 calorie diet would be approximately 166g fat 1494 calories (75%) and the remaining calories split 64g carbohydrate and 64g protein making the other (25%).

  2. Paleo isn’t necessarily a low carb diet. It’s more defined by not eating processed/modern agriculture foods. It just avoids grains/dairy/beans/etc. Many paleo people eat plenty of fruits/veggies/squash/sweet potatoes, etc…

  3. While most of the emphasis in Atkins is on the diet, nutritional supplements and exercise are considered equally important elements. The Atkins Diet represents a radical departure from prevailing theories. Atkins claimed there are two main unrecognized factors about Western eating habits, arguing firstly that the main cause of obesity is eating refined carbohydrates, particularly sugar, flour, and high-fructose corn syrups; and secondly, that saturated fat is overrated as a nutritional problem, and that only trans fats from sources such as hydrogenated oils need to be avoided.

  4. Interesting article Nick. Have you tried going keto for a few months?
    If you did, you would see that you won’t get “cranky” from missing a meal – your body can quickly start using bodyfat for energy, meaning your energy supply is never interrupted. In fact keto pairs very well with intermittent fasting.