Rules, Foods to Avoid, Benefits and Risks


The Slow-Carb Diet was first introduced in 2010 in Tim Ferriss’ book, “The 4-Hour Body.”

Ferriss claims that you can lose 10 to 20 pounds in the first month of The Slow-Carb Diet. Sounds great, but is it true? Is slow-carb eating any different than low-carb eating? Let’s get to the bottom of this.

What is The Slow-Carb Diet?

The Slow-Carb Diet promotes the idea that prioritizing particular, slow-digesting carbs and avoiding certain starchy carbs will promote quick weight loss and improved vitality and performance. Mainstays of the diet are proteins, legumes (such as lentils) and veggies, including fermented vegetables like kimchi.

The diet revolves around the idea that heavily processed carbs quickly digest, causing blood sugar spikes and leaving you hungry. On the other hand, nutrient- and fiber-rich slow carbs break down slowly, so you’ll have steadier blood sugar levels and feel more satisfied after eating.

The diet also promotes the idea of keeping meals simple. One of Ferriss’ key concepts is the minimum effective dose (MED) principle, which means putting in the least effort to produce your desired outcome. So, you’ll eat the same few meals on repeat.

The Slow-Carb Diet rules

The Slow-Carb Diet is structured around five main rules:

  • Avoid “white” carbohydrates or any that have the potential to be white. This includes white bread, rice, cereal, potatoes, pasta, tortillas and fried foods with breading. It also excludes grains of any sort, such as brown rice (which can become white rice after processing) and whole wheat (which becomes white bread after a trip through the manufacturing plant). There is one caveat: If you’ve completed at least 20 minutes of resistance training, you can eat these foods within the next 90 minutes.
  • Eat the same few meals on repeat. Focus on simplicity by eating from a limited variety of meals, particularly at breakfast and lunch. As Ferriss notes, many of us do this anyway, but in this case, diet diversity is discouraged for the sake of simplicity and staying within the allowed foods. It’s important to note that eating a diverse range of plant foods boosts gut health and helps you get all the nutrients you need.
  • Don’t drink calories. In addition to avoiding sugary drinks, The Slow-Carb Diet recommends giving up 100% fruit juices and milk. Instead, Ferriss says to stick to water, unsweetened tea, coffee and one to two glasses of dry red wine per night, if desired.
  • Don’t eat fruit. Fruits are excluded because Ferriss says they’re too high in fructose, a natural form of sugar. He claims that eating fruit leads to excess body fat, which is not supported by research, and fruits are a major source of fiber and antioxidants.  
  • Take one day off per week, and eat whatever you like. In fact, Ferriss suggests you “go nuts” on this day as a way to help manage cravings and boost your metabolism. And when he says go wild, he means it. Ferriss says he makes himself a little sick on his off day, so he doesn’t want to touch the foods he binged until his next cheat day. As a dietitian, I find this rule to be a glaring red flag, as research shows cheat meals can lead to disordered eating.

Foods to eat

The Slow-Carb Diet emphasizes whole foods that are high in protein and fiber. Key foods include:

  • Proteins: Meats such as chicken, turkey, beef (preferably grass–fed), lamb and pork; fish; and eggs.
  • Legumes: Lentils, black beans, pinto beans and chickpeas.
  • Vegetables: Spinach, kale, broccoli, cauliflower, asparagus, green beans, other non-starchy veggies and peas. Fermented veggies like kimchi and sauerkraut are also approved.
  • Fats: Healthy fats like olive oil, avocados and nuts are allowed, as is ghee.

Foods to avoid

To adhere to The Slow-Carb Diet, avoid the following foods:

  • Grains and starchy carbs, such as bread, pasta, rice, cereal and tortillas — whether processed or from whole grains. Potatoes and starchy veggies should also be avoided. The exception to this is if you’re eating a starchy carb within 90 minutes after resistance training.
  • Fruits, due to their natural sugar content.
  • Calorie-containing drinks, including sugary sodas, fruit juice and milk. 
  • Ultraprocessed foods with added sugars, preservatives and refined flours are off-limits because The Slow-Carb Diet focuses on whole foods.


The Slow-Carb Diet emphasizes whole, nutrient-dense foods, such as plant protein from black beans, lentils and other pulses, as well as non-starchy veggies. These foods are loaded with vitamins, minerals, antioxidants and other nutrients that protect your health. 

While The Slow-Carb Diet’s weight loss claims may be overstated, there’s a good chance you’ll shed pounds if you were used to eating a heavily processed diet and then eliminate those foods and start eating more whole and fiber-rich foods on The Slow-Carb Diet. 

Protein- and fiber-rich foods help you feel fuller longer, making it easier to eat within your body’s needs, which helps with weight management. When you’re physically satisfied with meals, it may reduce the urge to snack between meals, which can keep you in a calorie balance or help you achieve the calorie deficit needed to lose weight.

The emphasis on eating the same meals repeatedly is both a benefit and a downside. We make hundreds of food-related decisions every day, which can result in decision fatigue, and the more overloaded you feel, the harder it is to make healthy decisions about what to eat. The Slow-Carb Diet’s simplified meal planning philosophy can ease this burden, so you may be less likely to turn to pizza, fast food or another less-healthy option when deciding what to eat feels like an overwhelming task.


The Slow-Carb Diet has some drawbacks. For starters, it’s very restrictive and excludes many nutritious foods, such as fruits, starchy veggies and whole grains. These foods are loaded with nutrients, including fiber, and avoiding them could contribute to nutrient deficiencies. Plus, there’s plenty of evidence suggesting that a balanced eating pattern that includes healthy portions of these foods is associated with a healthier body weight. 

Because you’re only allowed to eat certain foods, the diet may feel monotonous and therefore challenging to maintain long term. You may still have intense cravings for off-limit foods, even though they’re allowed once a week. This could make the plan too hard to follow and less likely to support sustained results. 

In my opinion as a dietitian, the biggest problem is the weekly cheat day. A 2022 study suggests that just one cheat meal a week was linked to disordered eating. Because it promotes an all-or-nothing mentality toward food, it can harm your mental health, not to mention leave you feeling bloated and drained.

You’ll be much better off learning how to eat some birthday cake when a celebration arises or handful of French fries when out to dinner with friends than to postpone eating these foods until your weekly cheat day. 

Should you try The Slow-Carb Diet?

While The Slow-Carb Diet can be effective for weight loss and blood sugar control, it limits nutritious food groups that benefit your health. Between this lack of important nutrients and the diet’s restrictive nature, it may negatively impact your physical and mental wellbeing.

Balanced, nutritious and sustainable eating habits that teach you how to safely incorporate the less-healthy foods you love are more likely to lead to long-term success than a diet with gimmicky rules.

It’s also important to remember that healthy bodies come in all shapes and sizes. The goal isn’t to be the thinnest version of yourself but to maintain the healthiest weight you can while also enjoying a positive relationship with food and all the joys it brings, such as socializing with friends and loved ones.

If an eating pattern makes you feel obsessed about off-limit foods or causes distress, it’s a sign that it’s not the right plan for you. 

Instead of following a one-size-fits-all plan, consult a registered dietitian who can help you develop healthy and doable eating habits tailored to your goals.


Leave a Reply

Your email address will not be published. Required fields are marked *