Origins of The SCD 

The Slow Carb Diet (SCD) was created by Tim Ferriss and popularized through his book The Four Hour Body (4HB). The primary purpose of the diet is to facilitate fat loss although it can also be used as a way of eating to stay lean year-round. For good reason, the diet has amassed a cult-like following which, as I’ve written about before, is common among nutrition practices focused on dietary restriction (think veganism or keto). 

The SCD has helped thousands of people lose an average of 19 pounds of fat and some even lose up to 100 pounds total. Beyond that, I believe there’s great utility to this diet for those that are already at a healthy weight and want to stay lean year-round while eating a whole foods focused diet that I hypothesize may also be beneficial to overall longevity. I support this claim below, break down both positive and negative aspects of the diet based on my experience, and share how I’ve recently changed my thinking in regards to “cheat days.” 

The Five Slow Carb Commandments 

One of my favourite aspects of The SCD is that it’s simple. No thought is required to determine what you’re going to eat each day. For busy, high-performing people, which if you’re reading this I assume you are, this is optimal.

Peak focus and energy to perform high brainpower work are finite resources that we only have so much of in a day. The more decision-making horsepower you can reserve by eliminating simple decisions, such as what the day’s meals will consist of, the more you have in the tank to make more difficult decisions, perform deeply focused work, or motivate yourself to do the things you don’t want to do. The SCD eliminates mealtime decisions, here’s how it works. 

Rules one through four are followed six days per week, often Sunday through Friday, and rule five is followed one day per week, generally Saturdays. Although I’m covering 99% of what the diet consists of, Tim breaks down the finer points of the diet and addresses common questions in The 4HB.

If you’re considering giving this diet a try, I highly recommend picking up a copy. Beyond The SCD, there’s a ton of practical information in the book and I can almost guarantee that if you enjoy my articles, you’ll love Tim’s work. 

Rule #1: Avoid “white” carbohydrates (or anything that can be white).

• This includes all bread, cereal, rice (including brown), pasta, potatoes, tortillas, and fried foods with breading. If you have to ask, it’s probably a ‘no’. Your main source of carbohydrates will be legumes and beans (see Rule #2). 

• The only exception is that you’re allowed to eat these foods within 30 minutes of completing a strength session such as “From Geek to Freak” or “Occam’s Protocol”, which are strength programs detailed in The 4HB.

  • Personally, I ignored this exception and decided to steer clear of these foods at all times. Abiding by the maxim “know thyself”, it’s a slippery slope for me and once I start, it’s hard to stop. I do much better at following clear and defined rules I set for myself (yes or no) rather than trying to navigate grey areas (sometimes or maybe). I’d advise you to do the same unless your goal is to put on lean tissue in which case you may decide to eat “white” carbohydrates within a 30-minute time slot in moderation. 

Rule #2: Eat the same few meals over and over again.

• Meal Structure = Protein + Legume + Vegetable.

• Find 3-4 meals you like, each consisting of one pick from each of the three groups below, and repeat them. There’s no limit on how much of these foods you can eat (I repeat, NO caloric restriction), but don’t stray from the list. You can eat vegetables other than those listed below, but sticking to a few that you like makes shopping and preparation much easier. 

• Focus on eating between 3-4 times per day. Eat breakfast within one hour of waking, and if possible, within 30 minutes. This first meal should consist of 30g of protein, hence the coining of the ‘30 in 30’ rule (30g of protein within 30 minutes of waking). All other meals should consist of at least 20g of protein. Adequate protein intake as described here is critical to this diet. 

• Don’t get caught up on what seems like such a small selection of food. We already repeat the same meals, more or less, on a day-to-day basis. We’re just substituting those meals for ones with the foods listed here. 

• Proteins

  • Chicken breast or thigh

  • Beef (preferably grass-fed)

  • Fish 

  • Pork 

  • Eggs

• Legumes

  • Lentils

  • Black beans

  • Pinto beans

  • Red beans 

  • Soybeans 

• Vegetables

  • Spinach 

  • Broccoli, cauliflower, or any cruciferous vegetable 

  • Sauerkraut, kimchi

  • Asparagus 

  • Peas

  • Green beans 

Rule #3: Don’t drink calories.

• You can drink as much water, sparkling water, unsweetened tea, coffee (optional add-in: cinnamon), and any other no-calorie beverage of choice as you like. If you drink diet soft drinks, cap it at 16 ounces per day. You’re also allowed to have up to two glasses of red wine every evening.

• Steer clear of milk, non-dairy milk alternatives (soy, almond, etc.), soft drinks, fruit juice, and any other caloric drinks. The reason dairy is not allowed is that although milk has a low glycemic index, it has a high insulinemic response which is bad (insulin is a storage hormone). 

Rule #4: Don’t eat fruit.

• Humans did not evolve to eat fruit six days per week nor all year round. Depending on the origin of your lineage, there’s a strong chance your great ancestors didn’t have access to fruit for most of the year. Yet the lineage survived. You can meet your micronutrient requirements through other sources. 

• The reason this diet eliminates fruit (6 days a week) is that the principal sugar in fruit, fructose, is converted to glycerol phosphate more efficiently than almost all other carbohydrates.

  • Glycerol phosphate → triglycerides (via the liver) → fat storage.

• The only exceptions are tomatoes and avocados, both are okay to eat, the latter of which should not be consumed in excess of one cup or in one meal per day. Topping your meals with Salsa is also okay (within reason). 

Rule #5: Take one day off per week and go nuts.

• Saturdays, or whatever day you chose, are no holds barred. The four rules above go out the window on this day. You can eat and drink anything and in any quantity that you desire.

• Dramatically spiking caloric intake once per week can increase fat loss by spurring a host of hormonal changes (improving conversion of the T4 thyroid hormone to the more active T3, increasing cAMP and GMP¹) and ensuring your metabolism doesn’t downregulate due to extended periods of caloric restriction.

• This one day off per week also plays a huge role in helping you sustain the diet the rest of the week. After indulging in “junk food” on this day you look forward to getting back to meals of chicken, black beans, and spinach. In addition, just about everyone will break from a diet or binge at some point so it’s better to schedule it in advance so you can limit the damage (check out the Cheat Day Principles below). The psychological benefits arguably even outweigh the hormonal and metabolic benefits, as Tim states…

“I eat like this all the time and have for seven years. Few ways of eating (WOE) are this sustainable and beneficial.”

Cheat Day Principles

Principle #1: Minimize the Release of Insulin, a Storage Hormone.

• Insulin release can be minimized by blunting sharp jumps in blood sugar.

  • Ensure your first meal is not a binge meal. Eat something high in protein (30g minimum) along with insoluble fibre (i.e., legumes and spinach). The protein will decrease your appetite for the rest of the day. This can be a relatively small meal of 300–500 calories. If you drink coffee, add in some cinnamon to increase insulin sensitivity. 

  • Consume a small quantity of sugar from fruit (fructose) in grapefruit juice before your first crap-laden meal. Even small fructose dosing has an impressive near-flat-lining effect on blood glucose. If you want to extend the effects of caffeine, consume the grapefruit juice along with coffee. The naringin in grapefruit has this effect when consumed with caffeine. 

  • Use supplements that increase insulin sensitivity such as PAGG and AGG (part of PAGG)². This will help reduce the amount of insulin the pancreas secretes despite glucose spikes. 

  • Consume citric juices such as lime juice in water, lemon juice on food, or a beverage like citrus kombucha.

Principle #2: Increase the Speed of Gastric Emptying, or How Quickly Food Exits the Stomach.

• This can be done through consuming ~16oz of cooled yerba mate tea at the most crap-laden meals which contains three stimulants:

  • Caffeine (100–200 mg)

  • Theobromine (found in dark chocolate)

  • Theophylline (found in green tea) 

• Greens supplements, such as Athletic Greens, will also help.

Principle #3: Engage in Brief Muscular Contraction Throughout the Binge.

• Engage in 60–90 seconds of air squats, wall presses (tricep extensions against a wall), and chest pulls with an elastic band right before you eat and 90 minutes after eating. This brings the glucose transporter type 4 (GLUT-4) to the surface of muscle cells which effectively opens more gates for calories to flow into.

My Hypothesis: The SCD and Longevity

I believe that The SCD, well the first four rules of it at least, may be a beneficial way of eating for overall longevity. On a molecular level, the diet is very well designed to minimize spikes in, and fluctuations of, blood glucose.

Since the main source of carbohydrates in the diet are legumes, which are slow-digesting, rich in fibre, and the antithesis of a refined carb (known to spike blood glucose), one who adheres to this diet will likely have relatively stable blood glucose throughout the day. In addition, there’s zero added sugar in the diet which also contributes to maintaining stable blood glucose levels. 

The caveat to all of this being that one doesn’t actually know their blood glucose levels, or how it responds to certain foods, unless they wear a continuous glucose monitor.

The reason this is important is that blood glucose levels are one of the eight positive risk factors analyzed when determining risk for cardiovascular disease (CVD)³. Over time, consistently high blood glucose can lead to the development of a host of issues from diabetes to heart disease.  

Blood glucose levels are also inextricably tied to insulin secretion. In a healthy individual, one eats, glucose enters the bloodstream, the pancreas is signaled to secrete insulin which facilitates the storage of glucose in your muscle, fat, and liver cells to use for energy or store for later use.

Once glucose leaves the bloodstream, the pancreas ceases insulin production. If one develops insulin resistance, the muscle, fat, and liver cells aren’t as sensitive in responding to insulin which means they can’t efficiently take insulin and glucose from your bloodstream and store it. 

To compensate, your pancreas produces more insulin to overcome your increasing blood glucose levels. This is called hyperinsulinemia which means the amount of insulin in your blood is higher than what's considered normal. In short: Insulin resistance → Hyperinsulinemia → potentially Type 2 Diabetes (a metabolic disease). 

As I wrote about in The Four Horsemen, metabolic diseases are strong contributors to heart disease, cancer, and neurodegenerative disease which kill around 80% of people in Western nations. Long story short, it’s crucial to maintain stable blood glucose levels within a healthy range. The SCD may help us do that.  

Another reason to believe that this diet could be beneficial for longevity is that it’s completely whole food based. Each meal consists of a simple protein, legume, and vegetable. Very little to no processing and refining involved. In addition, there are stark similarities between The SCD and some of the diets most proven to be beneficial to longevity such as those from the Blue Zones and the Mediterranean diet. 

Of course, the likelihood that rule five of the diet, the cheat day, is beneficial to extending lifespan is abysmal but nonetheless, it still appears, anecdotally at least, to be a valid way of eating if your goal is to shed fat. 

The world of nutrition is a labyrinth and no one diet is going to be most optimal for everyone. However, it seems hard to make a case against a diet that focuses on, or at least integrates more of, legumes, protein, and vegetables unless one does the necessary bloodwork to determine otherwise.

My Experience 

Personally, I’ve eaten in accordance with The SCD for prolonged periods of time. Even when I’m not adhering to the diet strictly, I still tend to consume legumes in at least one meal a day and always ensure adequate protein and vegetable intake. Here’s a good ol’ fashioned pros and cons list for the diet based on my experience. 

Pros

• Cost effectiveness. Cans of beans usually cost less than $1. If you have the patience to buy dry beans and cook them yourself, you’ll drive down the average cost of each meal even more. Vegetables are also relatively cheap to buy. Buying meat can be expensive, but you’re more than making up for it in the money you’ll save by consuming the majority of your calories through beans. My personal philosophy when it comes to buying healthy food is, keeping in mind that I have a tendency to be “thrifty” in all other areas of my life, I don’t check the price tag. There’s no better investment than buying food that will help you achieve a healthy body and to me shopping around to save a few bucks here and there isn’t worth the time or emotional distress it causes me (I hate shopping).

• Decision-making horsepower. We have a finite amount of high-quality brain power and focus each day. I prefer to spend it on important problems and decisions rather than humming and hawing over what I’m going to have for lunch. When it comes to mealtime with The SCD, I go on autopilot. I know exactly what I’m going to make and how I’m going to make it. Often, I use the cooking time to passively sift through important or pressing matters in my head. If you want to further increase your cooking efficiency, and effectively decrease your time in the kitchen, try batching by doing all of your meal prep for the week on Sunday night. 

• No need to count calories. I’ve been able to stay extremely lean on this diet over long periods of time without having to pull out my phone in the kitchen to scan barcodes, perform mental math, and weigh foods as I cook.  

Cons

• Anti-Michelin Stars. There’s a slim chance you’ll look forward to your meals with an excited, mouth-watering optimism. But for me, that’s okay. I place more value on the positive aspects of the diet than the pleasurability of the meals. Not to say you can’t make good-tasting food on The SCD, but it certainly requires a little ingenuity and effort since you’re fairly restricted with the ingredients available to you. 

• Social peculiarities. Eating in this somewhat restricted manner may have an impact on certain aspects of your social life. If you frequently eat out, you’ll have to be more particular in the establishments you visit (Mexican restaurants are your best bet for SCD friendly meals) and get comfortable asking for modifications to your order. Life requires trade-offs. Take pride in your discipline and commitment to yourself and embrace the strange looks and comments you get. 

• I f*ing hate beans. Although I personally don’t mind them, if you feel this way you certainly aren’t alone. The solution? Olive oil (or macadamia nut oil), balsamic vinegar, salt, pepper, garlic powder, or any other low or no-calorie spice, seasoning, or herb of your choosing. If you hate the mouthfeel and texture, try fake mashed potatoes, which slow-carber Dana explains:

Put a little olive oil in a pan … add a can of white kidney beans (or some cauliflower), mash them with a spoon or whatever you choose, add a bit of water to get the consistency you want, season with a little bit of salt, pepper, garlic powder, and some parmesan cheese if you wish … tastes awesome and cooks in no time at all!

What I’ve Changed My Thinking About

Historically, I’ve long subscribed to a pattern of eating extremely healthy for most of the week and then having a “cheat day” or “cheat meal” once a week or every 10 days. This is common practice in the realm of bodybuilding, or more generally physique-focused exercise. I will admit that if you can adhere to a strict diet the rest of the week then, in my experience, this cheat day doesn’t seem to impede progress in striving towards an optimal body composition. 

Lately, I've started to rewire and change my thinking around cheat days. When I shifted my focus from physique optimization to a longevity practice, I started to question the impact of this day on my health. Surely it can’t be good for longevity. Besides that, I feel that the presence of a weekly cheat day has the potential to create an unhealthy relationship with food. If you feel like you need to binge once a week in order to eat healthy for the rest of the week, you’re likely not eating in a very sustainable manner. Of course, you can treat yourself sometimes but I think I’m still sifting through this problem and working to develop a healthy long-term approach.

That’s All, Folks

Whether or not you decide to give The SCD a try, I hope you’ve pulled out a strategy, tool, or tactic that you can deploy in your own life or have at least broadened your perspective on nutritional practices.

Keep in mind, there is no end game. We’ll be refining, tweaking, and modifying until our time is up. Experiment, eliminate, and adapt to formulate something that works for you. Here’s to constant and never-ending improvement (CANI).

Share Longevity Minded

And, as always, please give me feedback on Instagram or by hitting reply to this email.

Much love,

Jack

(Useful resources below)

Essential Minerals 

Potassium (4,700mg/day)

1. Lima beans, cooked, 4.9 cups (1 cup = 969 mg)

2. Chard, cooked, 4.9 cups (1 cup = 961 mg)

3. Halibut, cooked, 2.6 fillets (half a fillet = 916 mg)

4. Spinach, cooked, 5.6 cups (1 cup = 839 mg)

5. Pinto beans, cooked, 6.3 cups (1 cup = 746 mg)

6. Lentils, cooked, 6.4 cups (1 cup = 731 mg)

7. Salmon, cooked, 3.4 fillets (half a fillet = 683 mg)

8. Black beans, cooked, 7.7 cups (1 cup = 611 mg)

9. Sardines, 7.9 cups (1 cup = 592 mg)

10. Mushrooms, cooked, 8.5 cups (1 cup = 555 mg)

Magnesium (400mg/day)

1. Pumpkin seeds (pepitas), 2.6 oz (2 oz = 300 mg)

2. Watermelon seeds, dried, 2.8 oz (2 oz = 288 mg)

3. Peanuts, 1.6 cups (1 cup = 245 mg)

4. Halibut, cooked, 1.2 fillets (half a fillet = 170 mg)

5. Almonds, 5 oz (2 oz = 160 mg)

6. Spinach, 2.5 cups (1 cup = 157 mg)

7. Soybeans, cooked, 2.7 cups (1 cup = 148 mg)

8. Cashews, 5.5 oz (2 oz = 146 mg)

9. Pine nuts, 5.7 oz (2 oz = 140 mg)

10. Brazil nuts, 6.3 tbsp (2 tbsp = 128 mg)

Calcium (1,000mg/day)

1. Salmon with bones, 1.1 cups (1 cup = 919 mg) 

2. Sardines with bones, 1.8 cups (1 cup = 569 mg)

3. Mackerel, canned, 2.2 cups (1 cup = 458 mg)

4. Tofu, firm, 3.6 cups (1 cup = 280 mg)

5. Collards, cooked, 3.8 cups (1 cup = 266 mg)

6. Spinach, cooked, 4.1 cups (1 cup = 245 mg)

7. Black-eyed peas, cooked, 4.7 cups (1 cup = 211 mg)

8. Turnip greens, cooked, 5.1 cups (1 cup = 197 mg)

9. Tempeh, 5.4 cups (1 cup = 184 mg)

10.  Agar, dried, 5.7 cups (1 oz = 175 mg)