Fat Loss Forever: Summary & Review (Biolayne)

fat loss forever book cover

Fat Loss Forever (2019) is a nutrition book on how to diet effectively and keep the weight off forever.

Exec Summary

  • Calories are the #1 driver of both fat loss and nutritional health, and far more important than the type of food you eat (so don’t over-stress organic, whole, low-sugar, whole, processed, etc. etc.)
    • You can have any food, as long as it’s within your maintenance calories and macros. Demonizing and attaching ethical judgments to meals or food is a bad idea
  • Adherence to a calories-restricting diet is the #1 driver of fat loss, so you should choose your diet mostly based on what you can stick to
  • Your metabolism adapts, both to diets and over-caloric feeding. Unless you learn how it works, you’re almost bound to make mistakes with diets -or even to make things worse-
  • Nutrition is relatively simple but beware that the nutritional industry is packed with quacks, so watch out not to be lead astray by fake “gurus” and the latest fads


About the Author:
Layne Norton is a scientist, entrepreneur, pro bodybuilder (natural) and powerlifter, and a coach and educator on nutrition and training.
He holds a BS in Biochemistry and a Ph.D. in Nutritional Sciences from the University of Illinois (both with honors).

It’s All About Calories In, Calories Out

At the highest level, nutrition and weight are very simple.

A very simple equation governs weight gain or weight loss, be it from fat or lean body mass.
That equation is called “energy balance equation”, and it’s sometimes referred to as “Calories In, Calories Out”.

Such as, if you ingest more calories than you spend, you gain weight.
If you spend more calories than you ingest, you lose weight.

The 4 Components of Calories Expenditure

The “calories out” side of the energy balance equation is also known as your “Total Daily Energy Expenditure” (TDEE).

It’s a bit more complicated than the “calories in” part, and consists of 4 basic components:

  1. Basal Metabolic Rate: this is the major component of your total calorie expenditure (TDEE), accounting for around 60% (unless you’re a competitive trainer in some energy-intensive sport). Even if you stay completely put, you still consume energy through BMR just to stay alive, since it includes breathing, pumping blood, etc.
    Synonyms with just slightly different meanings and definitions include resting metabolic rate (RMR) and resting energy expenditure (REE)
  2. Non Exercise Adaptive Thermogenesis (NEAT) and Non Exercise Physical Activity (NEPA) This is the most adaptive component of metabolism. It increases significantly during a caloric surplus and decreases significantly during a deficit (ie., a diet). However, by how much the body self-adjusts also depends largely on the individual.
    Most resources, including this book, refer to both as NEAT
    1. NEAT includes unconscious little movements throughout the day such as typing on the keyboard, talking, fidgeting, wiggling your toes, etc.
    2. NEPA includes conscious daily and voluntary movements such as walking, standing, and any non-exercise activity.
  3. Thermic Effect of Food (TEF): the energy that it takes to extract energy from the food (digestion). Different foods have different TEF and, in general, higher fibers and proteins have a higher TEF (so eating 10 calories of protein in your body turns to just a little less than 10 calories of fat when measured outside your body)
  4. Exercise activity (EA): the calories you consume while exercising, which most people tend to over-estimate

Do Exercise, But Know That It’s Not So Important In Losing Weight & Fat

Remember that your metabolism:

  1. Adapts
  2. Defends a certain weight and fat ratio

That means that as your metabolism gets used to exercise, then the exercise simply becomes part of your metabolism’s own calculations, and won’t lead to any more fat loss outside of the very initial phase.
So it’s not like many people think that you can simply take your exercise calories expenditure, which many people overestimate anyway, and account that as “fat loss”.

Of course, this is not to say “don’t exercise”, because there are many more benefits linked to exercise.
It just means that you can’t out-exercise a caloric surplus and that calories matter more.

Say the authors:

We aren’t saying don’t exercise, because exercise has many other awesome health benefits besides weight loss. We also aren’t saying that exercise won’t help you lose weight. We’re just saying that it’s only going to give you an initial boost, and then it will become your new “maintenance” level.

Most of all, avoid exercising during the diet to quit it as soon as you end the diet: that sets you up for disaster.
It’s paradoxically better to never exercise at all than only doing so during the diet.

Instead, it’s best to increase exercise as you transition out of your diet.
Exercise lowers the body fat set point that your body defends and prevent the increase in fat cell number that sometimes happens during rapid weight-regain.
So, even if you regain weight, it will likely be less if you exercise.

Your Metabolism Defends A Certain “Fat Level”

People’s metabolisms tend to come with a pre-set level of “fat level” that they like to keep.

Say the authors:

the Self Defense System Body Fat set point theory is a widely accepted theory of metabolism. It suggests that each individual person has a level of body fat where their body naturally sits, and the body defends that level in an attempt to maintain it. Everyone has a different set point, as well.

This means that not everyone will attain a low body fat and maintain it on a decent amount of calories. It just may not be in someone’s genetic cards.
That doesn’t mean you can’t get better, healthier, and also have a better physique, but it means that you must be realistic -or that you must be ready for a draconian cut in food intake, and keep it that way-.

That’s also not to say that diets are not useful.
They’re extremely helpful, often even crucial for your health if you need one.

But it’s very easy to do those diets wrong, and only increase your body set points (keep on reading).

Your Metabolism Fights Against The Diet (Metabolic Adaptation)

Here’s what you need to understand:

Your body interprets a diet as an attack it needs to defend against. And the harder you diet, the stronger the attack, the stronger the self-defense.
Your body doesn’t know the diet is good for you.
For your body a diet is dangerous because it’s equivalent to scarcity and famine.

The self-defense system activates itself in 3 different ways to prevent diets from depleting your fat levels:

  1. Defend during the diet – by reducing your energy expenditure and becoming more efficient at squeezing the most possible calories from the less food you’re eating. This is why people hit plateus during diets
  2. Restore right after the diet – Increase the rate of weight regain and fat storage as soon as you consume more food (energy)
  3. Prevent future diet – Set in place mechanisms that prevent future diets from depleting your fat levels (for example, increasing the size and/or number of fat cells or increasing the hormones that make you feel hungry)

Efficient Metabolisms Easily Gain Weight

Most people think that those who gain fat easily have a less efficient metabolism compared to those who can eat a lot, without putting much weight.

Instead, it’s the opposite.
People who gain fat easily have a very efficient metabolism, efficiently turning all ingested calories into energy, with very little waste.
People who can eat a lot and not gain weight instead tend to squander and waste a lot of that energy with inefficient processes.

Of course there are other factors at play, as people who don’t gain weight often also move more. But if we look purely at metabolism, then those who get fat more easily are often more metabolically efficient.
And, if civilization were to collapse, they’d stand a better chance at surviving a famine :).

This is important to understand:

The Harder You Diet, The Harder It Becomes to Lose Weight

When you diet, your body actively fights against the diet because it wants to hold on to its reserves -the fat-.

Say the authors:

every time you diet (eat in a caloric/energy deficit), you are activating the body’s self-defense system. The more you attempt to diet, the stronger the signal to your body to strengthen this defense system.

Even exercise during dieting consumes fewer calories compared to non-dieting exercise.
Plus, your body automatically lowers your NEAT without you even realizing it. So while you decrease your “calories in”, your body is also decreasing your “calories out”.
Here’s an infographic from Fat Loss Forever:

Plateauing of fat loss during a diet is common due to “metabolic adaptation”: as your daily energy expenditure decreases, “calories in, calories out” balances and you stop losing weight because that original ‘deficit’ calories has now become ‘maintenance’ calories

Diets Make Your Metabolism More Efficient (at getting fat)

Because your metabolism adapts, and because it perceives diets as a famine to be protected against, diets prompt your metabolism to get better at extracting calories from food and better at storing fat.

So, in a way, diets make you become more like those people who get fat almost no matter how little they eat.

So during the diet, you make your body more efficient at turning less food into more fat.
And what happens when you end the diet?
Exactly, you’re going to feed a metabolism that has become super efficient at squeezing all possible calories from food:

research has also shown that when you increase food intake above maintenance after you’ve been dieting, your body more efficiently stores it as fat

And now the second big issue with diets:

The More Often You Diet, The Harder To Lose Weight In The Long Run (Yo-Yo Dieting Warning!)

Here’s the other catch:

The more often you diet, the more your metabolism wants to fight and prevent the next diets.
And it does have the ability to get better at defending against diets:

people who engage in this chronic weight cycling/”yo-yo” dieting for months, years, or even decades are further potentiating this self-defense system every time they do so.

One dangerous adaptation is that of increasing fat cell counts during a diet so that the body can store more fat as soon as food is available, so that it can fight back the next “famine”.
Of course, there won’t be any famine, so unless you’re very careful after you end a diet, you only get fatter, quicker.

Say the authors:

Essentially, what we’re saying is that if you regain weight too fast in the early post diet period, you might actually increase your fat cell number.
Increasing the total number of fat cells (hyperplasia) would make future weight loss efforts even more difficult and cause the body to defend a new, higher body fat set point.

However, don’t worry, if you do things well, you’re not doomed:

This is why good diets are progressive, and planned

Diets can be effective if you’re careful and if you take time to adjust once you end it.

Say the authors:

This is not going to happen to someone who regains all their body fat, but does so at a slowed pace. This situation likely only occurs in those who lose significant weight, then aggressively gain a significant amount back in a short period of time (likely a few weeks or less).


First, do not crash diet.
The more slowly you lose the weight, the more lean body mass you will retain. Maximizing your retention of lean body mass will help attenuate the slowing of your metabolic rate, because you’ll have more metabolically active tissue. It will also help prevent weight regain.

Indeed, the best diet is to diet while eating as much as you can.
This is because the more you can lose weight while still eating enough calories, the less your metabolism goes into self-defense mode.

If your metabolism is impared by yo-yo dieting you can still grow out of it with “reverse dieting”

Reverse dieting in short is:

a strategy of dieting where calories are increased in a controlled manner over time to increase metabolic rate while minimizing body fat gain.

The idea is to get your body out of that self-defense mode where it seeks to retain as many calories and fat reserves as possible.
By giving it enough food, your body will stop self-defending, and then you can restart your dieting the proper way.

Most Diets Are A Scam

Now that you understand how metabolism works, you realize that any:

  • Fast diets are poor diets
  • No diet can ever be truly “ended” without you regaining weight
  • You may have to make sacrifices, especially if your metabolism defends a high fat point, if you tend to be hungry, and if you like high-calorie food
  • There are no magic food, pills or supplements

Which is exactly how markets market their diet: fast, temporary, and “easy”.

Say the authors:

fad diet is only concerned with getting enough people to lose weight to put some nice before and after pictures on their cover.

Good Dieting Is Planned, Data-Based, & Sustained

So the key is planning, measuring, going at a controlled pace, adjusting, and sustaining the diet:

Success is only success if you can sustain the weight loss. Therefore, any form of diet you can’t sustain ought to be banned from consideration as a long term solution.

And as a stark warning:

if you cannot sustain the methods you used to lose weight, then the question is not “if” but “how rapidly” you’ll put back on the weight after you lose it.

In order of importance:

Since sustainability is crucial, it’s also crucial that you pick a diet that you like enough that you can stick to.
Such as: some effort and willpower are required, but the best diets limit the need for willpower because they’re the most suited to you, your preferences, and your lifestyle.
NO diet is superior to any other as long as it fits your calorie requirements: it’s what you can stick to that matters.

Some more tips for dieting:

  • Track your food intake if too tedious, track overall calories and proteins only
  • Make it hard to have energy-dense food
  • Plan to be flexible: such as, if you know you’ll have a big dinner you want to enjoy, eat less during that day. If you know that it will be very carb-heavy, have mostly proteins and fibers during the day
  • Eat similar food every day, which decreases appetite (but make sure there’s enough variety of nutrients)

How to calculate your maintenance calories intake

Probably the best way is by tracking and measuring yourself.

You track weight and food intake, and when your weight more or less stabilizes, you know you’re at maintenance calories.

Otherwise, if you want to calculate right now when you don’t have any data, the authors’ favorite is the Müller equation because it accounts for most of the variables that have the biggest impact on metabolic rate (LBM, FM, Sex, and Age).

It looks like this:

(13.587 × Lean Body Mass) + (9.613 × Fat Mass in %) + (198 × Sex) – (3.351 × Age) + 674 = BMR

Men put “1” in sex, women “0”.
For fat body mass you can use many instruments. None is super accurate, so the most important thing is that you remain accurate with it over time, using always the same instrument, and always at the same time of the day (the authors recommend a caliper).

How to Structure Your Macronutrients Intake

Remember that overall calories matters most!

That being said, you generally want to fill your macronutrients with enough protein first, then have enough fiber, and then you can choose for the rest.

  • Protein, min. 1.6 grams per kilogram of weight
    ideally with leucine. High protein meals lead to slightly -slightly!- more weight loss because of higher TEF and because for most people they tend to feel more satiating -most, not all!-. They also tend to spare muscle mass during a caloric deficit and promote more fat loss
  • Carbohydrates/fats: choose the split you like most and what helps you stick to the diet.
    Once you equate for calories, eating either more carbs or fats doesn’t make any difference in weight loss. So feel free to enjoy either as long as you eat just enough fats to keep your hormones in balance
    • Limit trans fats:
    • Don’t overdo saturated fats: it isn’t as bad as once thought, but still, don’t overdo it if you want to be on the safe side of heart diseases. Best of all is to replace saturated fats with PUFAs
    • Sugar: you can have it as long as you remain within your caloric threshold. But keep in mind that sugar isn’t very filling so you’ll probably be hungrier
  • Fiber: 10 to 15 grams of fiber per 1000 calorie intake per day
  • Alcohol: limit it, it’s nearly as energy-dense as fat at 7 kcal/gram, so consuming large amounts of it will be difficult to do while maintaining a caloric deficit. On the plus side, it has high TEF than carbs or fats.
    Generally speaking, if you’re drinking enough to get drunk, then you’re drinking enough to start having negative body composition side effects.

Remember: don’t over-stress it, and there are no advantages in over-consuming anything.
Especially fiber, that above a certain point doesn’t help your digestion any longer but backs you up.

Real-Life Applications

Do Exercise

If you never intend to be a physique competitor, you don’t need to spend an hour every day training. Even performing 30 minutes per day, three days per week of rigorous physical exercise can produce robust benefits compared to being sedentary

And if you can work it up to 1-2h, 4-5 days a week, you’re at a whole other level.
It must not be gym, of course, it can be biking, jogging, dancing, etc.

Exercise is especially important when you transition from a caloric deficit, to maintenance calories (when you end the diet).
And you want to keep exercising to keep the weight off.

That exercise must be purposeful and intense.
If you want lower intensity, then you have to make it longer. Walking is fine, but if that’s all you do, walk for 45 to 60 minutes every day.

Generally speaking, high energy in and high energy out (“high flux”) with more food but more exercise appears to be better for weight maintenance compared to a low flux energy state.

Avoid binge and “cheat days”

Refeeds are OK, but generally avoid that your high-calorie days exceed your low-calorie days by more than double.
Also, avoid the concept and mindsets around “cheat days” as it distorts food in terms of “good” and “bad”.

However, say the authors, that albeit there are no peer-reviewed studies, they observed from their coaching work that different people react very differently to refeeds.
Some people respond poorly, soak up and retain all the calories and grow ravenously hungry.
Some others instead feel satiated, and can even burst through plateaus after a high-calorie day or two.
So you must do your own self-analysis here.

Avoid Tom Bilyeu and all pop podcasters when it comes to nutrition: they invite the worst charlatans

Remember that marketers want to sell.
And the best way to sell is to come up with the newest fad, magical diet, or lists of foods to avoid.

Check out Layne himself:

Some common BS include:

  • Detox meals / food
  • Meal frequency “hacks”
  • The superiority of any type of diet for the general population (carnivore, “keto”, vegan, etc. etc.)


On putting health before “physique”:

A great physique isn’t going to make you happy. It might make you happier, but it’s not the key to happiness. I’m not sure what the key to happiness is, but I can tell you that it’s not having a six pack.


By the way, there’s no reason you can’t be a happy person and still have some body fat.


  • The author may not do himself many favors with a combative and argumentative stance

Sure, he directs his anger towards various people and conmen who talk out of their assess, so it’s understandable.

Yet, it may not help him.

It’s an issue that I also partially have whenever I smell bullshit: we both go very gang-ho, super direct.
That attitude does not help him (or me) to land many guest appearances and to spread his message.

You can also see it in the messages, and with yours truly as well 🙂

It’s not necessarily a con, though. And I frankly often enjoy that attitude. It tells you a low about how people reply to you.
For example, Mikhaila Peterson, Jordan Peterson’s daughter, challenged Layne to a “race between their children” to “prove” which diet was best -which tells you a low about who’s arguing on emotions-.
And Lewis Howes from “The School of Greatness” told him off when Layne proposed him to go on his show and dispel some of the bullshit (notice though Layne’s approach, which is quite power taking towards Lewis, and almost invites a defensive reaction. He might have been invited instead if he had approached him in a more friendly manner).

  • Some better editing would further help spread the wisdom

To me, this is a non-issue when the content is golden.
But to increase your reach, you may also want to look at how you present and share the wisdom -something I eventually had to also take care of here at TPM-.


It’s the best book I’ve read on nutrition, so that should say it all, and no point in a long list of “pros” which would include “well-referenced”, “logical”, “scientific”, “enlightening”, etc. Etc.

But just to list one:

  • Great introduction to flexible dieting

Not only Fat Loss Forever teaches how metabolism and diet work, but it also functions as an introduction to flexible dieting, which, in brief, would be:

You can eat whatever you want. You just can’t eat how much of it you want


Fat Loss Forever is simply the best book I’ve read on dieting and nutrition.

The second part of that sentence is most surprising, since the book is focused on dieting.

But, given how murky the information on general nutrition is, it’s both a compliment to the book, and a stain on the world of nutrition advice in general.

As a matter of fact, I wasn’t interested in fat loss and was hoping that Layne would make a book on general nutrition -Layne, are you reading here? Make one please! :)-.
But I ended up getting it anyway because, even with a focus on fat loss, it’s still the best book on nutrition I’ve ever read.

So, yeah, we highly recommend Fast Loss Forever.
As a matter of fact, at the time of writing, it’s the only book on nutrition we’d recommend, and Layne is one of the exceedingly few guys worth following and learning from.

Check the best books collection or get the book on Amazon.

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