The Slow Carb Diet debuted in 2010 with the publication of Tim Ferriss’s bestselling book The 4-Hour Body, but it still has a following today.
Advocates claim the diet delivers healthy weight loss results as long as you follow five simple rules and limit your food choices to exclude fast-acting carbohydrates.
In this article, you’ll learn how the Slow Carb Diet stacks up over a decade after its introduction with scientific research, pros and cons, and comparisons to the most popular diets today.
First, we’ll take a closer look at the ideas behind the diet, its rules, and which foods are allowed.
What Is the Slow Carb Diet?
The Slow Carb Diet is a simple, rules-based diet that emphasizes “slow-burning” or low-glycemic-index carbs.
The glycemic index (GI) of a carbohydrate is a measure of how quickly it raises your blood sugar after digestion.
According to slow-carb advocates, eating low-glycemic-index carbs and avoiding high-GI sources of carbs, like sugar, leads to easy weight loss without excessive hunger.
Factors that affect glycemic index include whether a carbohydrate is simple or complex, the amount of fiber per serving, and other macronutrients in a meal (additional protein and fats reduce the glycemic index of carbs)[*]:
- Low-GI or slow carbs (55 or less): Steel-cut oats, oat bran, muesli, sweet potatoes, peas, legumes, many fruits, and non-starchy vegetables.
- Medium-GI or moderate carbs (56-69): Some fruits, quick oats, brown rice, and whole-wheat bread.
- High-GI or fast carbs (70-100): White bread, corn flakes, white potatoes, pretzels, rice cakes, and popcorn.
Unfortunately, there aren’t any studies that directly confirm the effectiveness of the Slow Carb Diet, and a 2018 review concluded that “it is unlikely that the GI of a food or diet is linked to disease risk or health outcomes”[*].
Still, plenty of people have found it to be an effective diet for weight loss and other health benefits.
Before we cover the possible benefits and downsides more in-depth, keep reading to learn the rules of the Slow Carb Diet.
Slow Carb Diet Rules
At its core, the Slow-Carb Diet has five rules that set it apart from other diets:
- No white carbs. Any simple or complex carb that’s white or comes in a white form, including all bread, all rice, cereal grains, potatoes, pasta, tortillas, and breaded fried food. (Sorry bread- and rice-lovers, even whole grain and brown rice are off the menu.)
- No liquid calories. Soft drinks, lattes, fruit juice, and milk can be fattening. Even diet soft drinks may lead to weight gain[*]. Instead, sip water, unsweetened tea, coffee, or other calorie-free beverages throughout the day to stay hydrated and prevent cravings. White wine and beer aren’t allowed, but you can have 1-2 glasses of red wine per night.
- No fruit. Fruit contains fructose, which is not a slow-carb (although it can be when it occurs in high-fiber keto-friendly fruits). Some studies link overconsumption of fructose to high triglycerides, obesity, metabolic syndrome, and diabetes[*]. Tomatoes and avocados are allowed in moderation, however.
- Eat the same meals repeatedly to stay on track and lose fat. The theory here is that making unnecessary decisions around food leads to distraction and fatigue, so you’re better off making a habit of eating from a more limited menu (see lists and sample menu below) that works for your body.
- Once each week, take a day off and forget the rules. You can take a day per week and go wild, breaking any or all of the above rules. All foods and beverages are allowed. While it’s hypothetically possible to binge enough to offset six days of healthy eating, the idea here is that you’re better off psychologically if you can indulge sometimes. And overeating may temporarily boost your metabolism, too[*].
Note: a protein recommendation (not a rule) on the diet is to eat at least 30 grams of protein within 30 minutes of waking.
Foods To Eat
Here are the foods that are recommended for Slow Carbers:
Proteins
- Chicken breasts or thighs
- Beef, preferably grass-fed
- Pork
- Fish and seafood
- Cottage cheese
- Whole eggs or egg whites
Veggies
- Spinach
- Lettuce
- Cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, kale, etc.)
- Kimchi and sauerkraut
- Asparagus
- Peas
- Green beans
Legumes
- Lentils
- Black beans
- Pinto beans
- Red beans
- Soybeans
Fats, oils, and nuts
- Grass-fed butter
- Clarified butter (ghee)
- Coconut oil
- Extra virgin olive oil
- Nuts and nut butters
Note that many additional legumes, vegetables, and other foods not on this list are also acceptable, but you’ll be fine if you stick with the above recommendations, too.
If in doubt, you can always look up the glycemic index of foods and ensure that you mainly eat foods with a GI of 55 or less.
Foods To Avoid
Steer clear of these foods on the Slow Carb Diet:
- Liquid calories (except 1-2 glasses of red wine at night, optional)
- Diet soda and other artificially sweetened beverages
- All fruits (except for avocados and tomatoes in moderation)
- All sugar
- All bread
- All rice
- Cereal and cereal grains
- Potatoes
- Pasta
- Tortillas
- Fried food with breading
- Any carbohydrate that’s white in appearance
But remember, you can eat anything you want on your cheat day.
The Cheat Day
Once per week for a full day, you get to eat anything you want on the Slow Carb Diet. The “cheat day” allows for maximum flexibility and personal choice.
Psychologically and socially, many people find taking a day off from slow carbs and eating whatever they want is highly beneficial and helps them stay on their diet long-term.
Eating extra calories can also boost your metabolism, but if you go overboard, it’s also possible to end up with unwanted weight gain[*].
If your goal is weight loss on the Slow Carb Diet, monitor your results and consider scaling back your cheat day indulgences if you aren’t losing any weight.
Benefits
The Slow Carb diet emphasizes whole foods, and research shows that eating plenty of anti-inflammatory whole foods can reduce your risk of cancer, heart disease, and other medical conditions[*].
Further, it also excludes most unhealthy, inflammatory foods (except for during cheat days).
To sum up, like most diets (except keto, which is special), there are no special advantages to the Slow Carb Diet aside from the general benefits of eating nutritious foods and maintaining a healthy weight.
Risks and Downsides
There are no major risks to the Slow Carb Diet, aside from the possibility it may not be a good fit for your goals or body.
The most significant criticism of the diet is that it relies on the glycemic index to guide food decisions, but the glycemic index is not supported by scientific studies[*].
There isn’t credible research showing that following GI-based recommendations leads to better health outcomes or weight loss, and some evidence shows that GI isn’t actually good at predicting what it claims to predict (how quickly a food will result in elevated blood sugar)[*][*].
Another potential issue of the Slow Carb Diet is that it encourages users to select a few meals and eat them regularly for the sake of simplicity.
Eating the same thing all the time may be convenient, but some research suggests diets with greater food diversity are healthier, with more micronutrients, and reduce the risk of obesity[*][*][*].
How Does Slow Carb Compare to Low-Carb Diets?
The Slow Carb Diet is not a low carb diet, even though the name sounds similar. And it definitely won’t get you into ketosis.
A common definition of “low carb” is any diet that limits carbohydrate intake to 100 grams of carbs per day or less. Most low-carb diets are also high in healthy fats.
In contrast, people following the Slow Carb Diet could easily eat 50-60% or more of their calories from carbs, or 250-300 grams of carbs per day or more on a 2,000 calorie diet.
The keto diet, a very-low-carb, high-fat diet, typically includes 30-50 grams of carbs per day at most.
When you restrict carbohydrates, your body achieves a state of ketosis, which is responsible for many of the health benefits of going keto.
Overall, low carb diets like Atkins and keto are supported by abundant research, while there is no scientific evidence in favor of the Slow Carb Diet.
14-Day Slow Carb Sample Meal Plan
Day 1:
- Breakfast: Eggs fried in coconut oil and one-half avocado
- Lunch: Chicken thighs with pintos and peas
- Dinner: Grass-fed beef or steak, lentils, and mixed veggies
- Snack: Beef jerky or nuts
Day 2:
- Breakfast: Egg and spinach frittata with lentils
- Lunch: Grass-fed ground beef patties with lettuce, tomatoes, and black beans
- Dinner: Slow cooker pork loin with mixed veggies
- Snack: Cottage cheese
Day 3:
- Breakfast: Chicken fajitas with refried beans, sour cream, and salsa
- Lunch: Leftover pork loin with mixed veggies
- Dinner: Grass-fed beef or steak with lentils and mixed vegetables
- Dessert: Creamy almond butter with stevia and pumpkin pie spice
Day 4:
- Breakfast: Hard-boiled eggs, soybeans, and kimchi
- Lunch: Ground beef patties with lettuce, tomatoes, and black beans
- Dinner: Chicken thighs with broccoli or cauliflower
- Snack: Nuts or nut butter
Day 5:
- Breakfast: Egg and spinach frittata with lentils
- Lunch: Leftover chicken thighs with broccoli or cauliflower
- Dinner: Braised London broil with green veggies of choice
- Snack: Beef jerky or nuts
Day 6:
- Breakfast: Chicken fajitas with refried beans, sour cream, and salsa
- Lunch: Leftover London broil and veggies
- Dinner: Slow cooker pork loin with mixed veggies
- Dessert: Cottage cheese with stevia and cinnamon
Day 7:
- Breakfast: Egg and spinach frittata with lentils
- Lunch: Leftover pork loin with mixed veggies
- Dinner: Chicken thighs with pintos and peas
- Snack: Nuts or nut butter
Day 8:
- Breakfast: Beef fajitas with refried beans, sour cream, and salsa
- Lunch: Chicken thighs with pintos and peas
- Dinner: Grass-fed beef or steak, lentils, and mixed veggies
- Snack: Beef jerky or nuts
Day 9:
- Breakfast: Hard-boiled eggs, soybeans, and kimchi
- Lunch: Ground beef patties with lettuce, tomatoes, and black beans
- Dinner: Braised London broil with green veggies of choice
- Snack: Cottage cheese
Day 10:
- Breakfast: Egg and spinach frittata with lentils
- Lunch: Leftover London broil with green veggies of choice
- Dinner: Chicken thighs with pintos and peas
- Dessert: Creamy almond butter with stevia and pumpkin pie spice
Day 11:
- Breakfast: Eggs fried in coconut oil and one-half avocado
- Lunch: Leftover chicken thighs with pintos and peas
- Dinner: Grass-fed beef or steak, lentils, and mixed veggies
- Snack: Beef jerky or nuts
Day 12:
- Breakfast: Chicken fajitas with refried beans, sour cream, and salsa
- Lunch: Ground beef patties with lettuce, tomatoes, and black beans
- Dinner: Grass-fed beef or steak, lentils, and mixed veggies
- Snack: Nuts or nut butter
Day 13:
- Breakfast: Egg and spinach frittata with lentils
- Lunch: Chicken thighs with pintos and peas
- Dinner: London broil with green veggies of choice
- Snack: Cottage cheese
Day 14:
- Breakfast: Hard-boiled eggs, soybeans, and kimchi
- Lunch: Leftover London broil with green veggies
- Dinner: Ground beef patties with lettuce, tomatoes, and black beans
- Dessert: Creamy almond butter with stevia and pumpkin pie spice
Note: This sample Slow Carb meal plan doesn’t include any weekly cheat days, but if you want to use them, you can eat whatever you want on days 7 and 14, which will extend the sample meal plan to 16 days total.
Conclusion: Slow Carb Diet vs. Keto
The Slow Carb Diet plan dates back to 2010, and it’s probably helped thousands of people lose weight.
Even though the application of glycemic index doesn’t appear to be based on sound science, there’s still a chance the rules and food list could work for you.
If you’re trying to decide between Slow Carb and low-carb, though, today’s science is clear on which approach is more effective.
In the intervening decade, research has shown that the ketogenic diet offers unique health benefits as well as weight loss without counting calories[*].