The Problem With Crash Dieting

Philip Pape 0:01

When you decide to lose 20 pounds or more , what is the first thing that you typically do ? If you're like most people , you probably jump straight to cutting calories , trying intermittent fasting , cutting food groups like carbs , or following some quick-fix diet something unique , something new that promises rapid results in maybe as little as a few weeks , and it seems to make perfect sense . Eat way less food , lose way more weight right . But what if the most common approach to losing those 20 plus pounds , the one that feels the most logical and that everyone seems to try first and say is working for them is actually setting you up for failure ? Today , I'm going to show you why the most popular weight loss method might be sabotaging your results and , more importantly , what the science says you should do instead .

Philip Pape 0:51

The allure of rapid weight loss is everywhere . You see before and after photos all over the place claiming that someone dropped 30 pounds in 30 days . You see influencers and hear podcasters recommend extended fasting or detoxes or eliminating food groups to slim down , and the message seems clear If you want dramatic results , you've got to go for dramatic measures . But what if those common approaches to dieting in fact , most of the named diets out there are all really just crash diets that make things worse in the end . And what if there was a more intelligent way to lose substantial amounts of fat while preserving muscle and maintaining long-term metabolic health ? Today , we are breaking down the science of why most diets fail , what actually happens in your body when you cut calories too aggressively , and how to approach fat loss in a way that creates lasting results , even when you do have 20 , 30 , or 40 or more pounds to lose . Now , before we get into it , if you are tired of the cycle of aggressive dieting followed by rebound weight gain , I do offer a free 15-minute rapid nutrition assessment , which is a call without a sales pitch , where we get on Zoom for 15 minutes and identify what's been holding you back . We create a simple , science-based plan usually two or three steps that works with your body , based on what I've learned about you in our conversation . And that's it . You go along your way with a little more clarity and some action . All you got to do is book your free call using the link in the show notes and hopefully I'll be talking to you soon .

Philip Pape 2:25

All right , First let us define exactly what we mean by aggressive calorie restriction or crash dieting , because when I titled this episode the Worst Diet . The irony there is that I would never recommend a best diet . In other words , the best diet is going to be the one that is most personalized to your needs and your level of flexibility and rigidity , and that's the point . And so when I talk about a worst diet , I'm also not talking about a single diet . I'm talking about an overall philosophy or approach that the vast majority of people use , probably 95% or more , because that's the amount of people that fail to maintain the results . Therefore , it's not working . It's not working . So if you tell me , no , keto worked for me , I'm going to ask you well , are you still doing it and is it still working for you ? And if you say yes and yes , and I feel great and it's everything that promised and more then awesome , guess what ? That is the diet that works for you , but the vast majority of people it's not the case . So what do we mean by these approaches ? All right , I'm going to give you some criteria

Red Flags of Crash Dieting

Philip Pape 3:29

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Philip Pape 3:29

These are the red flags . If any diet has these , then it's a red flag and probably not going to work . The first one is just that they're asking you to cut calories to some extremely low , usually arbitrary level . If I were to give a number on that , I would say for women that's well below 1,200 calories . For men it's well below 1,500 . Understanding that , it is highly personal . If I have a client who weighs only 100 pounds or 110 , she's a very petite female , she might be dieting at 1,000 and it feels just fine , with no hunger and no metabolic issues . But she's a lot smaller . Her body doesn't need nearly as much energy coming in , so it's not as restrictive for her . Similarly , with a male , smaller in stature , maybe lower in weight , he might find that 1,400 or 1,500 calories is fine for dieting . Others , myself included , anything below 1,800 feels very restrictive . So a diet that tells you you've got to eat this many calories like Optivia I think it's 800 calories Ridiculous . That is a huge red flag there .

Philip Pape 4:28

The second one is that it promises an outcome like a certain amount of weight loss in a certain amount of time . That is unsustainable . So usually that's well more than two pounds per week . And again it depends on your body mass , right ? A 300 pound person losing two pounds a week , that's actually totally reasonable . A hundred pound person losing two pounds a week ? That would be highly concerning . So I like that as just a general average , but usually they're promising something that just sounds good enough to be great for marketing , right ? I lost this many pounds in this many weeks and it just sounds almost too good to be true , but not quite , but it's probably too aggressive .

Philip Pape 5:09

The next red flag is that they're telling you to cut foods out , and so this is the red flag that , honestly , the vast majority of diets pin themselves on Food groups like carbohydrates or fat . Most diets don't tell you to cut protein thank goodness , although maybe we're going to see that next but even specific foods . They'll tell you to not eat these specific foods because they are insert fear-mongering adjective here inflammatory . It drives me crazy , right ? So if anything tells you you can't eat something , that's a red flag . And then the next one is if it tells you you have to fast or switch up your meal timing to a certain feeding or fasting window , that is a red flag as well , because , again , there is no right or wrong feeding window . It's going to depend on what works for you across a variety of factors .

Philip Pape 6:00

Fasting myths that have to die and that was the point of that episode was to talk about how none of the claims for fasting actually hold up in terms of them being superior to non-fasting . They may work for you , but they are not superior . And so that's the red flag is if it says you have to include certain fasting windows . And then the final red flag is that they claim to reset or boost or fix your metabolism , with the caveat that I probably have used adjectives similar to that , either inadvertently or in a colloquial way , because it's great for marketing , and I admit that I'm trying to do that less and less now . I don't think I use the word reset . I definitely don't use the word fix . I'm pretty clear that you cannot damage or harm your metabolism . The word boost , yeah , I've used that , but I usually use it in the context of the philosophy of boosting your metabolism through having more muscle mass or moving more , things like that . But a diet that says eat this way and it's going to boost your metabolism , that is the red flag , all right .

Philip Pape 7:03

So I want to break down today's episode , which I have no idea how long it's going to be , but it's an important topic . I actually broke it down into four segments to make it more accessible . I'm first going to talk about why crash diets . They seem logical and pretty and neat , but they lead to poor outcomes for some very clear reasons , and once you understand them , you know to look for them when it comes to assessing diets . Number two is the science of how your body adapts to aggressive calorie cutting , because that is the root of a lot of the problems people have . Number three is I'm going to give you five specific ways that crash dieting makes fat loss specifically harder , and then , finally , the alternative based on evidence that works for you to give you the sustainable results that I think you're looking for and why you're listening to this podcast .

Philip Pape 7:49

So let's start with why crash diets seem to make perfect sense , and the logic goes something like this we know that we need a calorie deficit to lose fat . All right , now , if you don't accept that to begin with , go back to Nutrition 101 , energy balance , physics , thermodynamics , whatever you want to call it . It is an absolute fact that we need to eat less than we burn to lose weight on the scale and ultimately then to lose fat to lose meaningful fat . Can you lose fat and build muscle at the same time ? Yes , and then we're getting into nuances , but in general , you need a calorie deficit . So if a 500 calorie deficit leads to losing one pound per week , then a thousand calorie deficit should mean losing two pounds , right , and then a 1500 calorie deficit , even faster . So just cut as many calories as you can , eat as little as you can , you're good , right ?

The Pitfalls of Crash Dieting

Philip Pape 8:39

The problem with this linear way of thinking is it ignores the fundamental complexity of human physiology . Your body is a very sophisticated system , and it adapts to protect you from what it perceives as a threat to survival , to homeostasis , to vibrancy and vitality . Right . When you cut calories too aggressively , you are triggering a bunch of sensors in your body . You're triggering a cascade of protective adaptations that are going to make fat loss way more difficult . And if you think about it from an evolutionary perspective , our bodies evolved during times when food was often scarce and the ability to adapt to reduce calorie intake by becoming more efficient with energy use was then crucial for survival . And so this isn't a flaw in our biology . It's a really amazing feature that helped keep our species alive .

Philip Pape 9:31

And so this brings us to the science of how your body responds to aggressive calorie cutting , because when you suddenly drop your calories very low just , we're talking not a normal calorie deficit , but a very aggressive calorie deficit , which you will have from many diets . When you cut out a bunch of foods , you cut out a bunch of processed foods , cut out a bunch of carbs or even go on one of these weight loss drugs , for example , you're going to have potentially a huge drop in calories , right , because you don't have an appetite for the drugs in particular , but also because you cut out calorie dense foods . And so what happens ? So let's say , you drop well more than 500 calories a day . First , your BMR , your basal metabolic rate that is , the energy you burn at rest begins to decrease beyond what would be expected from weight loss alone , because when you lose body mass , your BMR goes down .

Philip Pape 10:20

But we have found that research from , in fact , dr Eric Trexler and others have been involved in this research shows that the adaptation that occurs can reduce your daily energy expenditure by 200 to 300 calories within weeks of starting an aggressive deficit , and I've seen , over time , clients' metabolisms drop by up to 600 , 700 , 800 calories over a long time . But they can happen quickly , especially when it's aggressive . And then , second , your NEAT , your non-exercise activity thermogenesis all the movements you do outside structured exercise naturally decreases . You fidget less , you take fewer steps , you generally move less throughout the day , right , and a lot of it's unconscious some of it's conscious , but a lot of it's unconscious and studies show that this can account for another two to 400 calorie reduction in your daily energy burn , right . Third , then you have your exercise activity thermogenesis how many calories you burn during your training , your workouts , your structured cardio all of that becomes less efficient . The same workout literally burns fewer calories as your body adapts to preserve energy . You actually become more efficient during fat loss . One study found participants burned 20 to 30% fewer calories doing the same exercise after 12 weeks of aggressive dieting . So it stacks on top of itself .

Philip Pape 11:42

And then on top of all of this is that hormone levels shift to keep you alive , to preserve your energy , to preserve your existing precious fat storage , which is very important from an evolutionary standpoint . So this means decreased thyroid hormone production , reduced testosterone and growth hormone , increased cortisol , changes in hunger and satiety hormones like leptin and ghrelin , right . And these are not permanent . That is very important to understand . These adaptations are temporary . They're your body's natural , reversible response to what it perceives as a threat , and the problem is that crash dieting it's like a threat , it triggers them . It triggers these adaptations much more dramatically than a more moderate calorie deficit , even though any deficit's going to trigger them to some extent . Crash dieting triggers them much more , to the point where you're kind of past the precipice , and it makes it very difficult . So then this brings us to five specific ways that crash dieting makes sustainable fat loss harder .

Philip Pape 12:45

We're sort of connecting these concepts of what happens to specifically when we're thinking of fat loss . All right , number one accelerated muscle loss . This is the whole purpose . When we're trying to lose fat but not lose muscle and improve our body composition , this is the whole purpose . When we're trying to lose fat but not lose muscle and improve our body composition , this is the whole purpose of keeping a fat loss phase moderate . Actually , when you cut calories too aggressively without adequate protein and resistance training , that's the worst case .

Philip Pape 13:12

Research shows up to 40 to 50% of the weight lost can come from lean mass . So a lot of you out there , if you're listening and you're not strength training , you're not eating enough protein . Don't go into fat loss yet , because you're going to lose muscle and then you're not going to lose fat , or you're going to lose some fat but you're also going to lose muscle . That's the problem , you know . I think somebody tried to argue with me about this on I don't know where it was on YouTube and say , like , show me the research that says you don't lose fat when you lose . And I said no , no , no . The issue isn't that you don't lose fat , it's that , along with fat , you lose a bunch of muscle . I'd rather you lose only fat .

Philip Pape 13:47

Another study found that aggressive dieters lost twice as much muscle as those taking a moderate approach , even with the same total weight loss . And again , this is all accelerated when you're not training , when you're not eating protein , when you are lifting weights and you are eating protein , you can actually mitigate this quite a bit , and that's why you can go somewhat aggressively , depending on how long it is , and not lose muscle . But again , that's a little bit more of an advanced strategy once you've got all this stuff dialed in . And I talked about that on other episodes , such as the January 6th New Year's episode about six ways to lose fat in 2025 . So check that one out Now .

Philip Pape 14:25

Why does all this matter ? Right , muscle tissue we know it burns more calories than fat when it's at rest . Right , and so we want to have more muscle for a variety of reasons . But that's just from a metabolic and from a calorie burning perspective . It's going to make fat loss harder when you don't have the extra muscle and you start to lose it and your metabolism decline accelerates , and that's the worst thing we want to happen , all right .

Philip Pape 14:48

The second thing is that you'll get increased hunger and cravings , well beyond what you would if you were at a moderate deficit . So it's almost like an exponential curve . The more aggressive you cut , the more you ramp up those hunger and cravings because the hormonal adaptations that happen . They are making you hyper-focused on food . For a reason and you've probably heard maybe have heard of the famous Minnesota starvation experiment , which gave us a lot of research that we still rely on today Participants in that study became obsessed , literally obsessed , with food . That's all they can think about . They had intense cravings . Many developed binge eating behaviors that persisted after the study . So that alone , from a sustainability perspective , if you think about dropping your calories to the point where you can tolerate it versus past that point , that makes a big difference on whether you're successful .

Philip Pape 15:40

Number three here is compromise training performance . So because we are trying to prioritize fat loss and not muscle loss and therefore we want to train , we also want the fat loss itself to not chicken and egg us out of training properly , right ? So if you don't have enough fuel , so if you don't have enough fuel , if you don't have enough recovery , your workouts are going to suffer . And I guess the irony is that we are deliberately cutting down on fuel and recovery by going into a fat loss phase . So we have to find the right balance , otherwise you just can't push as hard , you can't lift as heavy , you can't maintain the proper intensity , get that stimulus for muscle preservation and then you'll burn fewer calories and it all stacks on top of itself . So think about training and performance . That's huge .

Philip Pape 16:25

Number four is psychological burnout , mental burnout , right ? Extreme restriction , then , requires willpower , and that is not something we have to rely on . Is willpower , discipline and always being on and consistent and perfect ? No , we don't want to have to rely on it . We want to enjoy our life and the fact that life is fluid comes and goes . Stress comes in and out , people come in and out . Our situation changes weekly , if not daily , right ? And we know that willpower is this finite resource .

Philip Pape 16:53

Psychology tells us that most people hit a breaking point pretty early on if they go too aggressively and then you realize that this fast , quick fix type of deal is not all it's cracked up to be . It doesn't even give you the result , even if it's just pure weight loss . Oftentimes you won't even get it because you can't stick with it . You hit a breaking point . Only the people who really white knuckle it out , that really just stick with it with their discipline yeah , they'll finally get it . You hit a breaking point . Only the people who really white knuckle it out , that really just stick with it with their discipline yeah , they'll finally get it . And then they're still going to have all the other problems like muscle loss and hunger and everything else . So then it just becomes impossible and that's not sustainable .

Philip Pape 17:25

The last one number five is the rebound weight gain . Studies are consistently showing between 80 and 95% of crash dieters regain the weight within one to five years . Right and remember , crash dieting is something that adheres to any of the red flags that I mentioned earlier . So don't think that you are not crash dieting because you're doing keto or you're doing intermittent fasting . There is a crash dieting aspect to that that's going to make it unsustainable . And then , more concerning is when people fail to sustain the results , they actually usually end up heavier than their starting weight because they've lost muscle mass . So not only they're heavier , they've got even higher percentage of body fat at that heavier weight . And now they've prolonged their metabolic adaptation which , although I mentioned it's temporary , there are aspects of it that permanently change . If your body composition has changed , granted , you can come back and restore it with bringing back your muscle mass , with losing some body fat , but know that that is what happens . So what's the alternative to all of this ? What do you actually want to do ?

Speaker 2 18:32

Hi , my name is Jenny and I just wanted to say a big thank you to Philip Pape of Wits and Weights for offering his free 50-minute nutritional assessment . During that time he gave me really good tools on how I can further my health and fitness goals . He asked really great questions and stayed true to his offer of no sales pitch . I have since applied these things and gotten really close to my health goals and my weight goals , and now I'm able to flip over and work on my strength and my muscle conditioning using a lot of the things he offers in his podcasts , and I just am very grateful for his positive inspiration and encouragement , for all of our help . Thank you , philip .

Philip Pape 19:18

All right , I'm going to break it down into just three key principles that I think are the most important . Sometimes I can go down a rabbit hole and give you like a million things to do . These are three principles that I work with all my clients to incorporate as part of their skill set , and if you just think about these , write them down , put them on a post-it , put them on your fridge , they're going to go a

Keys to Sustainable Fat Loss

Philip Pape 19:37

long way . The first principle of sustainable fat loss is doing it moderately , like doing all things moderately . Create a moderate deficit , right . Create a moderate deficit that allows for adequate nutrition , energy performance , while still getting you the result . So moderate for you is going to be moderate for someone else . I usually talk about a sweet spot of around a half percent 0.75% of your body weight a week . Some people might be lower , some people might be higher , some people it's a lot lower . You may be the type of person that has a fairly low metabolism , not a lot of wiggle room , and you've got to go at like a 200 calorie deficit a day and it's going to take you many months to get to the number you want . Well , so what ? You're going to get there as opposed to either not get there or get there in the wrong way and lose a bunch of muscle , make it unsustainable , regain the weight all the things we just talked about . So the moderate rate of loss is actually a very important principle to think about because it can override all the other trade-offs you're thinking of . Right , if you're thinking , okay , I'm going to speed it up at this point because nothing's going on in my life , but it causes a lot more hunger , you might not stick to it . Right , if you are trying to hit a certain date and then you go at a faster rate of loss , you might end up losing muscle . So there's a lot of reasons not to do it aggressively . There are a small subset of reasons where you can do it aggressively , but again , that's beyond the scope here when we're talking about general principles for sustainability .

Philip Pape 21:09

So the moderate deficit is number one . The second one is that muscle preservation , and I put that as a catch-all principle because then it causes you to think of your protein intake and your resistance training together , but also things like carbs . So it kind of ekes into different aspects of this . We want enough protein , but we also want enough carbs . We also want to train consistently , but not so much that we over-train or don't have recovery during fat loss , that we're starving or whatever , and it kind of forces you to think about all those things . It helps you maintain your metabolic rate . It ensures that weight loss comes primarily from fat tissue and you're going to have better body composition outcomes .

Philip Pape 21:47

And then the third principle here is planning in diet breaks and recovery periods . So , combined with the moderate loss , the preserving muscle , then the breaks allow you to think about your life . This is where many people go wrong . They think they want to just keep pushing harder when progress slows or they're going to keep going , going , going , going and never stop . But we know that taking planned breaks up at maintenance calories is going to help you , and so we're going to talk about that . And yeah , while it gives you a short physiological break , it's mainly a psychological break and then it teaches you . Oh , I can do this for a long time because I know that I can accommodate parties and holidays and travel and trips and it's not a big deal . I'm just taking a quick little pauses along the way , and that is also part of principle number one of being making it sustainable and moderate in terms of the rate of loss , all right . So hopefully that all made sense to you guys , and I like to think in terms of an engineer , you know that . And so what we're doing is we're building a system .

Philip Pape 22:48

When I say what's the worst diet , it's the diet that doesn't give you a system for making it work for you . But what does a good system look like ? Well , a good system is going to be efficient , which means you use minimal resources , and that can include mental resources . It's reliable , meaning you know if you do it it's going to get you a result consistently . Three , it has to be sustainable . So that means you've got to be able to do it and turn the crank , no matter what's going on in your life . You can keep doing it over and over again . You could ostensibly do it forever . I mean a true fat loss phase . We want it to be a fixed duration , but you're going to be able to do the process no matter what life throws at you , even if you adjust the scale or the magnitude of it . And you'll be able to take breaks . You'll be able to periodize and those sorts of things . And then the fourth thing about your system is it should be adaptable . So I kind of just alluded to that . But it needs to be able to respond to changing conditions , no matter what . Like , you've always got plan B , c , d , you always have . If , then and it's kind of built in right A crash diet fails every one of these criteria .

Philip Pape 23:56

It's inefficient because , well , the main reason it's inefficient is it wastes muscle tissue , so it doesn't even get you what you want right , and so , by definition , it just fails . It's unreliable because the results are going to vary wildly . I can't guarantee that you're going to have a certain body composition coming out of it . It's just so chaotic . It's also unsustainable because it just fights against what your body's trying to do . Because it just fights against what your body's trying to do , or put another way , it causes your body to over-respond when it comes to homeostasis , hormones , muscle loss , body fat storage , etc . And then it is inflexible because there is nowhere to go when progress stalls , except just eat less , and that's the worst thing .

Philip Pape 24:37

Whereas a moderate approach checks all the boxes , preserves muscle , produces results that are reliable , you're confident , you can do it . It works with your body's adaptations . It also leaves room for adjustments to work with your life whenever you need to , and that's all the time , let's be honest . So , while the crash dieting might seem faster initially , it takes longer to reach your goals when you factor in the recovery time , the rebound , weight gain , the loss of muscle and I hope I couldn't make it any clearer than that . Okay , I don't think I said that right . I don't think I can make it any clearer than that .

Philip Pape 25:11

So the worst weight loss diet isn't really a diet , it's the approach and it's the mindset that that approach creates . It's something that teaches you to view your body as an enemy , which is not what you want . You want to work with it , right . It promotes an unsustainable and all or nothing mentality , a poor relationship with food , and there's no way you can have lasting change under those conditions . But if you're armed with science , like we covered today , and what actually works , a flexible approach , you can be among the less than 5% that choose a different path that respects your body's superiority , in that your body knows what it's supposed to do . It delivers the results you want . It builds sustainable habits and preserves the muscle and the metabolic health that make long-term fat loss possible . And , of course , if you are ready to create your own sustainable fat loss plan , if you want a little bit of expert guidance .

Philip Pape 26:06

Go ahead and book that free 15-minute rapid nutrition assessment with me . It is not a sales call , it is a hey , how you doing . Let's get to know each other , tell me what's happening , and here's a few things you can try that are going to give you some clarity . We'll identify what's been holding you back . We're going to create a simple , science-based action plan , and I usually end up sending you some guides or resources along with that if not a workout program , for example and it's going to help you lose fat ? It will . It's going to help you maintain muscle . It's going to help you maintain and improve your metabolic health . Just by applying those principles , click the link in the show notes to schedule your free 15-minute rapid nutrition assessment . And with that , until next time , keep using your wits lifting those weights and remember the best approach isn't the quote-unquote fastest one , it's the one that lets you maintain your results for life . I'll talk to you next time here on the Wits and Weights podcast .