I went the exact opposite route. After losing 180 pounds via bariatric surgery and then regaining 70 of it, I dove into the science. I read books, but only books that pointed directly to scientific literature I could read. More importantly, I learned how to differentiate good nutrition studies from bad nutrition studies (hint: at least 90% of nutrition studies are bad) so I could tell when an conclusion is warranted by the data versus when it isn't. I also started completely ignoring anything said in the media, since, invariably, they get it wrong or they hype the afore-mentioned bad studies. Everything became about the science and the n=1 experiments.
What I found was that I could lose weight without effort, improve every health marker, and enjoy the foods my body really seemed to desire (as opposed to foods engineered to cause cravings). The 70 pounds disappeared without any tracking of anything[1]. More importantly, that 70 pounds was gone a year ago, and maintaining the loss has been just as straightforward.
I applaud anybody who finds the method that works for them. It's pretty clear our bodies are striving to be healthy and get what they need; once you find that, the rest comes relatively easy.[2]
1. There was some early tracking as I learned about different foods and how they interacted with me and my goals.
2. Unfortunately, some people lost the genetic lottery (less than you might think) or are so metabolically disturbed (becoming more and more) that it isn't always easy. I have a huge amount of respect for those who persevere through that and work towards a healthier life.
Hmm, tough question. Here are some of the studies that struck me most. The danger of something like this is it can look like confirmation bias; that is not the case. It just happens that a close, impartial reading of the evidence tends to lean one direction.
* Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women[1]
* Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance[2]
* The ketogenic diet as a treatment paradigm for diverse neurological disorders[3]
* The ketogenic diet reverses gene expression patterns and reduces reactive oxygen species levels when used as an adjuvant therapy for glioma[4]
* A Systematic Review of the Evidence Supporting a Causal Link Between Dietary Factors and Coronary Heart Disease[5]
At the time, I wrote a wikia article[6] that tried to distil all of my thoughts and what I had learned. It is mostly correct, but I'm sure I got some things wrong. I haven't gone back over it in some time.
More recently, I think this article (Dietary Carbohydrate restriction as the first approach in diabetes management. Critical review and evidence base)[7] gives a good overview of the metabolic benefits.
All of this does not imply that I think a ketogenic diet is the One and True Path(tm); it is far more nuanced than that, but that's not a bad place to start for a lot of people.
This is good info, the only things I would add here:
* carbohydrate intake should really depend on your activity level. I'm guessing the majority of the people in these studies were sedentary so a ketogenic diet is a pretty good option. People who are more active should consume some carbohydrates because glycogen depletion tends to mess with energy levels.
* A higher dietary protein intake has been shown to increase satiety and lead to weight loss by itself. Regardless of your diet you should increase your intake of high protein foods; beans and low fat cultured dairy are good sources.
Steve Phinney and Jeff Volek have done a lot of research into high performance athletes using a ketogenic diet (see, for instance, The Art and Science of Low Carbohydrate Performance[1]). Extreme endurance athletes are using ketogenic diets as a tool to smash records in ultramarathon running[2].
Nobody needs carbohydrate. That doesn't mean carbs are necessarily bad, but the long-time trope that you have to have them if you want to move further than your couch is just silly and has long been disproven (if, by nobody else, hunter-gatherers who had gone days without food while running down a kill).
Phinney and Volek have found interesting things about fat and high-intensity exercise:
* Fat utilization in keto-adapted individuals that is, literally, re-writing textbooks. Levels of fat mobilization that have never been seen in laboratories is being recorded. This likely has a genetic component, what I would consider the opposite of the multiple copies of the amylase gene that highly carb-tolerant people seem to have.
* Fat requires less oxygen to utilize, leading to less lactic acid, less muscle tissue damage, and faster recovery.
* Keto-adapted athletes are much more efficient in their use of their glycogen stores, using less when passing 70% VO2-max and replenishing supplies faster. They do not store as much glycogen as carb-burners, so the net effect winds up being about the same amount of power from glycogen between carb and fat burners.
That doesn't mean there are no athletes who would see benefits of carbs, but, in a fat-adapted state, those carbs can be much, much more strategic in nature (the cyclist sprinting over the hill, the olympic lifter in competition, etc). Peter Attia talks a lot about his strategic use of carbs while exercising[3].
Personally, I see beans as a food to be very cautious with. The phytates, lectins, and saponins in them are there to protect the seed, since plants can't run away to protect their offspring. They use chemical warfare, and are quite good at it, leading to poor absorption of nutrients[4]. Properly preparing them (soaking and fermenting) can address this problem, something done in all societies previous to the 20th century, but rarely done now.
I also can't see any reason to use low fat, well, anything. Fat is a perfectly healthy macronutrient, and, when going for low fat, you are typically getting a lot of sugar and additives put in to replace the taste and texture of the lost fat. On the other hand, live-cultured dairy products, for those who can tolerate lactose, are an amazing food.
+1 ketogenic...in fact for me, lost 100lb on ketogenic, then slowly added back carbs (increasing exercise) gained back 20lb. went back on ketogenic, isocaloric and less exercise...immediately dropped back down
Carbs soak up water, so it's natural that you would gain weight when adding carbs and lose weight when you remove them. That's why doctors and nutritionists say not to worry about your weight, but worry about your waist. Weight can be misleading.
The amount of carbs stored in the human body would not account for 100 lbs, not even for 20 lbs. A couple of pounds of carbs are stored in the body, in the form of glycogen, plus the water it soaks - maybe three times more, so the difference may be about 8, maximum 10 pounds.
I would certainly worry about 20 lbs gain, carbs or no carbs.
Yes. The only way the carbs are stored in the human body is in the form of glycogen, in liver and skeletal muscle. There's about 1 kg of it in total, maybe a bit more if you're a trained athlete. And glycogen binds about, maybe, up to 3 times as much water by weight. So, altogether, about 4 kg.
After switching to keto, glycogen is used up gradually, due to no carbs entering the body. And the water is also lost. Therefore, the "signing bonus" of the keto diet - a significant weight loss in the beginning, but due to water lost, not fat burned.
BUT. That only accounts for about 4 kilos, maybe just a bit more. You can't really blame water for a gain of 20 pounds.
No one ever said it could account for 20 lbs. Merely that you should expect weight loss when you're cutting carbs and weight gain when you reintroduce carbs.
Sounds like you studied very hard, worked very hard, learned something very valuable and verified that it works at least for you. What you've learned could help a lot of people (like me :). I hope that you find a way to share it with the world.
Look at my response to beaumartinez nearby. For a deeper dive, I wrote up more in the 6th reference I link to there. If you have more questions, please feel free to email me; my email is in my profile.
Wow! I totally did not know this. Just went through a few Wikipedia articles too.
A question I have is what would happen if I cut down carbohydrates, but not increase fat either! I discovered through accidental self-experimentation that cutting down on sugar is helping me, while my diet barely included rice, potatoes, etc. anyways. I used to consume some pasta, but will reduce that too now.
What is the purpose behind increasing fat in diet when doing this? Is it to just compensate for calorie loss? Is it to control cravings? One one hand, it is saying that ketogenic diet will help burn body fat, and on the second it says go increase fat consumption!
I'll need to do some research to understand how to get carbohydrates to just 20-25 grams per day like you have mentioned. A "Pure Protein" bar I just consumed by itself had 17g! Would it work out if I can get to within 50g of carbs (which is still much lower than 300g you mention for an average American), together with cut down fat too? Or that defeats the whole purpose?!
Since I started cutting down on sugar drastically, I have noticed though my craving for sugar has increased (though I am still able to control). Diet soda seems to be helping with these cravings significantly though I am not sure what are the side effects. (I have come across many conflicting studies against soda, so have never been sure!)
I am moderately exercising too, gradually increasing.
Eggs seem to be recommended in these diets. As someone with borderline cholesterol, would eggs still be recommended?
So feel free to eat as many eggs as you wish (but as with all things diet, moderation is generally a good idea, 2 dozen eggs a day is probably not going to do great things for your health).
On the total carbs thing - American wrappers tend to include fibre in the total carbs- European ones don't, and you should read up on 'net carb' - but basically, take the fibre value off the total value. If it's ok to do that, it'll look something like:
Total carbs: 15g
-- fibre 9g
-- that sugars 3G
What is the purpose behind increasing fat in diet when doing this? Is it to just compensate for calorie loss? Is it to control cravings?
It is both. Firstly, for an average person, carbs are a significant part of calorie intake. If you just drop them, and drop fat at the same time, where will you get your calorie intake from? You'll only be left with protein, and it's not so easy to get all your calories from protein. Besides, there is no benefit in reducing fat further than required to achieve some caloric deficit. And also, many people find the combination of fat+protein in meals satiating.
One one hand, it is saying that ketogenic diet will help burn body fat, and on the second it says go increase fat consumption!
You don't get fat from eating fat. You also don't get fat from eating carbs. You get fat from eating too much calories. The goal is to reduce the amount of calories in a sustainable way. Some do it by eating many small meals, some by 1-2 large meals. Some do it by reducing carbs, and some by reducing fat. Try and see what is the easiest for you.
A "Pure Protein" bar I just consumed by itself had 17g!
Try to stick to fresh, unprocessed foods, if you can - it's healthier, but also easier to avoid "carb creep" by added sugar and other sources of carb. Fresh vegetables, meats, fish, poultry, eggs, nuts, cheese, cream are very compatible with keto.
Eggs seem to be recommended in these diets. As someone with borderline cholesterol, would eggs still be recommended?
This is a very controversial subject, and there are multiple books written, and they contradict each other. Ask me for a book recommendation if you wish. :)
In short, there are two separate issues:
1. Does dietary cholesterol raise blood cholesterol, and
2. Does blood cholesterol cause heart disease?
Overall, it appears that there is still no proof that cholesterol causes heart diseas - most, almost all evidence is just correlation. Eggs appear to be safe regardless of some studies that demonize them. And, just for fun, the following link (it's not a proof of anything as it is n=1 anecdote)
Normal Plasma Cholesterol in an 88-Year-Old Man Who Eats 25 Eggs a Day — Mechanisms of Adaptation
I, personally, would recommend against doing this, especially if those meals contain carbohydrate or protein. The problem (and I realize Evgeny probably knows this) is that eating many small meals keeps insulin levels consistently high (both carbs and protein cause insulin to be secreted). While we don't have the direct evidence of it yet, most biological system, when exposed to a cellular input constantly, down-regulate the receptors for that input. Down-regulating insulin receptors is the definition of insulin resistance and insulin resistance is the first step towards diabetes.
Well, I have to admit - there is no proper scientific proof beyond any doubt. Obviously, to prove the statement, one would have to keep two groups of people locked in the lab for years, feed one group with fresh food, and the other group with processed food, and compare the health of both groups at the end.
Then there would be endless arguments: which particular types of food are harmful, and maybe they can be eaten in moderation without any harm at all, and so on, just like the battles that are currently going on around sugar ...
However, there are multiple cases where the introduction of "Western foods" to people who were eating traditional diets caused significant increase in "diseases of civilisation". I personally started from reading "Nutrition and Physical Degeneration" by Weston A. Price - it is available for free online.
To generalise more, unprocessed foods have more fibre. Increased fibre is proven to reduce cancer incidence; eg[1].
(Of course, one can eat processed food and add fibre from another source. Nevertheless, the advice to eat unprocessed food is reasonable as a generalisation).
As you hang around the keto worlds, you will hear a lot about the "evils" of Ancel Keys, the founder of the "saturated fat causes heart disease" movement. Even he didn't believe dietary cholesterol had an impact on heart health. A few things to know:
* The original panic about dietary cholesterol came from feeding rabbits high cholesterol diets. It turns out that herbivorous rabbits are particularly poorly suited for a diet high in animal fat. Go figure.
* Your body has a cholesterol "set point": an amount of cholesterol it wants for daily activities like building cell walls, repairing tissue, making hormones, etc. If you do not eat it, your body will make it. If you eat it, your body won't make it. Regardless of your diet, the end result is the same.
* There has never been a causal relationship shown between cholesterol in the blood (much less diet) and coronary disease. Since cholesterol is part of the immune response, it is, quite literally, like saying we need to remove fire fighters because wherever we find them, we find fires.
Don't be afraid of the cholesterol. Now, there are some numbers that have some correlation with heart disease, but every single one of those numbers are improved by a low carb, high fat diet. See several of this points in this[1].
On getting carbs down, there are a few things to recognize:
* There are gradual improvements. For people who are "carb intolerant", every carb removed from the diet comes with an improvement in general health. If you can't get to 25g to start, try 75g (note: I had serious issues with carb cravings, so I could not do this; it had to be all or nothing).
* There is a step, going from "sugar burning" to nutritional ketosis (generally defined as >=0.5mmol blood ketones), that, for most people, causes a significant increase in energy, clarity of thought, etc. Some people don't experience that and may do better with slightly higher carbs. Experimenting is good.
* It takes a few weeks to get the body fully converted to burning fat (keto adapted). During that period, it is not uncommon to feel sluggish, have headaches, have strong sugar cravings, etc. This can and does pass (many of the older papers showing how "bad" keto diets are ended after 2-4 weeks, right in the middle of keto-adaptation).
There is a strong reddit community[2] that is worth checking out, with a lot of good "how-tos".
On calories, my advice is to always start eating to satiety. During the first few weeks, as craving hit, feed them with fat (bacon is particularly good). Don't worry about calories at all for the first two months as you become keto adapted.
After 6-8 weeks, start really paying attention to your body. Eat when hungry, stop eating when you get full. Your body's satiety signals will usually start working correctly again when the insulin levels are lowered.
Most people will find that their appetite self-regulates into a pattern that causes fairly consistent loss (there may be some plateaus, but that is normal). If you are in this category, just keep going. Worry about your carbs and nothing else.
If you find that you aren't losing "automatically", don't automatically assume you need to force reduce what you eat. Look for other things like too much stress, too little sleep, food intolerances (wheat and dairy impact a lot of people), etc. before trying to will-power your way to loss. Your body wants to be healthy, so find what is keeping it from being there (some people have a really unhealthy relationship with food, so fix the relationship rather than just axing the food).
You are welcome to email me any questions as well. My email is in my profile.
What I found was that I could lose weight without effort, improve every health marker, and enjoy the foods my body really seemed to desire (as opposed to foods engineered to cause cravings). The 70 pounds disappeared without any tracking of anything[1]. More importantly, that 70 pounds was gone a year ago, and maintaining the loss has been just as straightforward.
I applaud anybody who finds the method that works for them. It's pretty clear our bodies are striving to be healthy and get what they need; once you find that, the rest comes relatively easy.[2]
1. There was some early tracking as I learned about different foods and how they interacted with me and my goals.
2. Unfortunately, some people lost the genetic lottery (less than you might think) or are so metabolically disturbed (becoming more and more) that it isn't always easy. I have a huge amount of respect for those who persevere through that and work towards a healthier life.