Slow Carb vs Keto

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Written by Myra S. Hussain, Medical Doctor and medically reviewed by Abby Courtenay

Imge of Slow Carb vs Keto



Carbohydrate restricting diets are gaining a lot of traction nowadays. Amongst an array of diets, ketogenic and slow carbohydrate diets have managed to become quite popular for all the right reasons. 

Both aim to reduce body fat percentage by lowering calories through limiting or modifying carbohydrate consumption. Though keto has been around for a while now and many people have adopted this lifestyle, a slow carb diet isn't far behind. 

Recently the relatively lenient slow carbohydrate diet has attracted the attention of fitness enthusiasts. It's almost like keto but not quite. Both have ample positive effects on health and both help you lose weight.

This article will shed some light on how keto and slow carbohydrate diets are different from each other. It should also answer all your queries including what are the pros and cons of each, whether there are any side effects and which one is better for you.


What exactly is the slow carb diet?

This weight loss plan was developed by Timothy Ferriss in his 2010 book The Four Hour Body

There are 5 main rules to follow on the slow carb diet:

  1. No “white” carbohydrates (bread, pasta, cereals)
  2. No high-calorie drinks
  3. No fruit
  4. Repeat the same meals
  5. One day a week, you can eat whatever you want

So, what can you eat on the Four Hour Body plan? 

  • As much as you want of low-carb vegetables, animal protein (meat, poultry, fish), eggs, and legumes.
  • Small amounts of fats and spices.
  • Dairy is not allowed (except cottage cheese).

In this eating plan, your carbs are coming from sources that are slow to digest, like lentils, beans, and non-starchy vegetables.

How are slow carb and keto similar?

In practice they're quite different, but the two diets do share a few common features. 
So how are slow carb and ketogenic diets similar? 

  1. Both ways of eating are aimed at weight loss.
  2. Both are low in carbs.
    • You avoid carbohydrates made with refined flour, such as bread, pasta, and baked goods. 
    • You avoid fruit juice and soda.
  3. Both emphasize eating low-carb vegetables.

Working out is not a hard and fast rule in either of the two, therefore you have full control of your physical activity. It is, however, recommended that you get adequate physical exercise. 

Both of these diets emphasize that you quit poor-quality carbohydrates not just temporarily. Consider this change a lifestyle improvement that is good for your health and fitness.


Differences between slow carb and keto diet

At a first glance, both appear pretty similar, but a closer inspection reveals that they're not identical. 


First and foremost, the goal of a ketogenic diet is to keep carb intake low enough to induce a state of ketosis in your body. This way, you start burning fat for fuel. 

This doesn’t happen in the slow carbohydrate plan. While it does eliminate some types of carbohydrates (refined flour, fruit), other foods containing carbs can be eaten in unlimited amounts (lentils, beans, most vegetables). 

Since the carbohydrate restriction is not as strict on slow-carb, ketosis is not usually achieved.


A ketogenic diet advocates a drastic increase in healthy fats as a replacement for carbohydrates. 

The Four Hour Body plan allows fats, but recommends you eat small amounts.


The working theory behind these diets also differs greatly. 

Slow-carb is based on simplicity. There are 5 basic rules to follow, and each week you get to take one day off from the diet.

Keto is based on the science of ketosis. You have to be intentional about not going over your carb limit each day. This leads your body into a state of nutritional ketosis, which means your liver starts producing ketones from fats, therefore using fat as the primary fuel source.


Benefits of slow carb and keto

Both have their own set of benefits, and that's probably why these diets have amassed a cult following in the health and fitness industry. 

Here are a few advantages of a slow carbohydrate diet:

  • It keeps you full for longer as you consume a balance of slow carbs, fats, and proteins.
  • It is associated with lesser food cravings and hunger pangs.
  • You lose weight 
  • Unhealthy processed carbs are removed from your meals.
  • Your energy levels are consistently maintained for longer periods when you're consuming slower-burning carbohydrates.
  • High protein and fiber content help maintain healthy blood sugar levels.
  • You get a cheat day every week.
  • Easier and cheaper to execute for long durations.

Similarly, keto also has its own set of benefits:

  • It has been shown to help many people achieve faster short-term weight loss.
  • Keto may be helpful for weight loss, acne management, and other symptoms in PCOS patients.
  • Can reduce risk of cardiovascular disease through weight loss and increasing HDL cholesterol.
  • Researchers have also found that the keto diet may have neuroprotective effects, especially in diseases like Alzheimer's and Epilepsy.


Side effects of slow carb and keto

Every diet tends to have some side effects and health risks that you need to be careful about. 

Here are some complications that might arise while you're on a slow carb plan:

  • You might overeat during cheat days and minimize the weight loss you worked so hard for.
  • You might experience low energy levels at times.
  • Slow carbohydrate tends to limit fruit intake (which limits certain nutrients).
  • Sometimes micronutrient deficiency can arise if you skip supplements or your diet doesn't contain a variety of foods.
  • Any restrictive diet can worsen disordered eating. 

The ketogenic diet also has its drawbacks, here are a few notable ones:

  • You may experience keto flu which has symptoms like brain fog, headaches, vomiting, agitation, nausea, and hypoglycemia.
  • It can be difficult to stay on keto for longer periods.
  • Keto can also increase the risk of kidney stones.
  • A ketogenic diet can also lead to micronutrient deficiency. 
  • It can also worsen health conditions like pancreatitis and eating disorders.


Keto versus slow carb foods

So what kind of foods can you consume on these diets? 

On a slow carb diet, you may be eating lots of vegetables, legumes, meat, poultry, fish, and eggs. You can also have fats, herbs and spices, and low-calorie beverages like tea and coffee. 

Foods allowed in keto are a bit more restrictive, and keep in mind that you also need to measure how much you eat to avoid eating too many carbs. 

Both diets discourage the consumption of some of the same foods like bread, starchy food, sugar, honey, baked goods, and fruit juices. 

Here's a chart that can better help you understand what you are and aren't allowed to eat in each of these diets.

Beans and legumes In moderate amounts
Condiments and sauces ✔ (low carb) ✔ (low sugar)
Dairy Most dairy is discouraged (except on cheat day)
Sugar-free drinks
Sugar-sweetened beverages
Alcoholic drinks ✔ (low carb) ✔ (in moderation)
Fish and seafood
Fruits In moderate amounts Only on cheat day
Grains and starches In moderate amounts In moderate amounts
Herbs and spices
Meat and poultry
Nuts and seeds
Oils and fats In moderate amounts 
Processed foods ✔ (low carb) Highly processed foods are discouraged
Sugar-free sweeteners
Natural sweeteners
White and brown sugars
Starchy vegetables In moderate amounts Selective vegetables
Non-starchy vegetables


This comparison between the two clarifies that they're not identical. 


Is slow carb cheaper than keto?

It's no secret that restrictive diets can be a bit expensive. 

If you have a limited time, going keto can be a difficult task. Highly processed items like low-carb bars and specialty products can drive up the cost of keto. If you don't have time to cook your meals, buying pre-cooked ketogenic meals can be even more costly. 

However, on both diets you can have fresh non-starchy vegetables and low-cost meats and poultry, which are generally more affordable foods. 

So, how much you spend depends on how you do your grocery shopping and how much time you have available to cook your own meals.


Which diet is healthier, slow carb or keto?

Each diet has its beneficial effects and merits. Both can help you shed weight and improve your lifestyle quite a bit. 

Slow-carb has been proven more sustainable in the long run since it’s not as restrictive. It also has minimal adverse effects on your health. 

On the other hand, the power of ketosis can have positive impacts on your health when a keto diet is followed in a healthy way (limiting saturated fat and highly processed foods). For example, it should be noted that keto may reduce certain symptoms of  diseases like polycystic ovarian syndrome (PCOS) and epilepsy.

Each individual is different, so it’s best to consult with a doctor to determine which might have the most benefits for your personal situation.


Final verdict

Depending on your current health status, fitness goals, endurance, and weight loss aspirations, either one can be the right choice. 

The slow carb diet may be easier to do for longer periods since it has a cheat day built in every week. But the effectiveness of keto should not be denied. Physicians and fitness gurus have expressed their confidence in keto and its ability to induce weight loss in a short period. 

So if you're looking to shed extra pounds fast, then keto may be the way to go. On the contrary, if you're looking for a lifestyle change that can help keep you healthy and fit while still allowing you to indulge once a week, then slow carb might be the right choice for you.