Is 800 calories a day unsafe?

Philip Pape 0:01

Is 800 calories a day unsafe ? The answer might surprise you because it depends entirely on who we're talking about . A 105-pound woman has vastly different energy needs than a 300-pound man , yet programs like Optivia push 800-calorie diets on everyone . Today , we are going to cut through the confusion around very low-calorie diets . You'll learn why there's no universal unsafe calorie number , how to determine your own metabolic limits using biofeedback and data , and the critical trade-offs between aggressive deficits and sustainability .

Philip Pape 0:50

Welcome to Wits and Weights , the show that helps you build a strong , healthy physique using evidence , engineering and efficiency . I'm your host , certified nutrition coach Philip Pape , and today we're going to tackle one of those highly debated questions in fitness Is 800 calories a day unsafe ? And I picked 800 on purpose , because sometimes people say 1200 or 1500 , and we're going to get into these nuances . But I picked a really low number because the question comes up all the time . Given our cultural obsession with magic numbers , with universal thresholds and set points , we act like 800 or 1200 calories is the universal floor for women and 1500 for men and that anything below that for everybody is automatically dangerous . But the reality is , as always , more nuanced than any arbitrary threshold and it depends on context , constraints and individuality ,

Weight loss programs vs. real science

Philip Pape 1:43

and I love the fitness industry and I say that sarcastically . You know Instagram . They love to exploit confusion , confusion across the board .

Philip Pape 1:52

Companies , weight loss programs they market things that are ridiculously extreme , to be honest , and they do so via fear . They spread fear about things like metabolic damage . We still hear that term . Your metabolism is broken or damaged , not a thing . And then you are left wondering if that lower calorie target is going to help you reach your goals faster or it's going to sabotage your metabolism . Why can this program do this ? But then this influencer over here says that's way too low , and I made this episode because one of our Physique University members actually asked the question said like I've heard that X number of calories is too low . Is that true ? And I wanted to address this because it's a very relevant topic . There is a rise in rapid weight loss and , yes , rapid fat loss too , but sometimes they get interchanged incorrectly .

Philip Pape 2:42

We know about Optivia , which has been around a long time , and I have clients that constantly come to me saying , yeah , I tried Optivia in the past . It was miserable . I was down 800 calories and you weren't supposed to exercise and it was just arbitrary , regardless of your size , your activity level , your metabolic needs , not even the very basic quote , unquote personalization . And then we're also seeing more research on physician supervised very low calorie diets for obesity . And then we're also seeing more research on physician-supervised very low-calorie diets for obesity . And we're seeing , with weight loss medications , very low-calorie diets , intentional or not . We're seeing research on diabetes reversal , pre-diabetes . And that adds all this complexity to the discussion where you're like , well , what's the thing that I'm supposed to go with ? And , by the way , it's actually quite simple . What's hard is implementing it for you . We're going to get into that .

Philip Pape 3:28

But before we get into the specifics , I do want to share something that Julia from Physique University recently told me . She said quote I joined WWPU and finished the onboarding today . I'm glad I'm here . Before I thought it's just more information and better organized as is possible to soak up in the podcast , but I started to feel that the community and support are really the resources which will finally move the needle for me . Now this , I'll say , perfectly captures things that obviously I'm not marketing as well myself , and that is that it's not just about the information , it's how we implement it right . Individualized approaches matter so , so much .

Philip Pape 4:09

And Julia realized shortly after joining . Because , again , apparently the way I market it isn't good enough to show you this that generic information , even if it's helpful , even if it's evidence-based , like we talk about on the show , is not enough . She needed personalized guidance to find what worked for her unique situation . So if you're ready to do that , let's say you've been listening to the podcast for a while and you want to stop guessing about all these things , including calorie needs . But that's just scratching the surface . You really are looking for a system designed specifically for your body , for your goals , for your constraints , for your preferences , right ? These are all important things . Physique U is where we make that happen , where we help you determine your metabolic needs , your hormonal situation , your training situation , and create a sustainable plan that preserves muscle while achieving your physique goals . You can learn more about that at the special link in the show notes , because only that link is going to give you a free nutrition plan that I will build for you , because you're a podcast listener

Why one-size-fits-all diets fail

Philip Pape 5:10

and I love to give stuff away . So go to the special link in the show notes to join Physique U , get the free plan and we'll see you in there .

Philip Pape 5:18

All right , let's talk about why this question about calorie levels and whether 800 calories or 1200 or whatever is unsafe , even matters , right , it comes down to fitness culture . We're obsessed with magic solutions , formulas , the one best fit answer , right ? The one thing you know . You've probably heard again that women should never go below 1200 calories or 1,500 calories , and these often get thrown around as if they're universal laws of physics , but they're completely arbitrary . Here's the reality . Okay , let's get into numbers .

Philip Pape 5:52

A sedentary 105 pound woman Okay and I've worked with some clients that are in that range might only burn 1,200 calories per day at rest . That is her total metabolism , not even RMR or BMR . We're talking about her total daily energy expenditure . You add in , you know , even more neat walking movement on top of that . Maybe she pushes it up to 1500 . She had some muscle mass , right , she does all the healthy lifestyle things and she's still burning 1500 calories . So for her , at 15 or 1600 calories , even eating 1200 calories is just a very moderate deficit , like 25% deficit . Right , it's small , it's not going to even feel like starvation . I mean , I've worked with these clients before and I've had them on the show before , in fact , where they'll say you know what ? This is what my body needs it feels okay . And so if you're 105 pounds and you burn , you know , between 12 and 1600 calories , then eating a thousand calories may be totally reasonable for your deficit .

Philip Pape 6:51

Now eating 800 , even at that level tends to be pushing it for most people . It doesn't mean it's unsafe . It depends on the deficit and how long you go , and the reason I wanted to start with that question for this episode is to suggest that there really is no good answer to that . I would say unsafe is relative to how aggressive your deficit is , how long it is and how it is affecting you right Now . Compare that to . On the other extreme , we have people that are 300 pound plus , who might be burning 3,000 calories at rest . A male , for example , who burns 3000 calories is not uncommon at all . Somebody who lifts weights in fact doesn't have to be 300 pounds , it could be 225 , 250 burning that much . So for him , 800 calories , like actually an actual intake of 800 , would represent a massive , ridiculous , extreme . Yes , unsafe deficit . It would be like 70 , 75% , okay , and that would be extremely difficult to sustain outside of clinical supervision . And having said that , I recently onboarded a client who weighs about 250 and he had done Optivia at 800 calories and told me how miserable that was . And it's not like he died , right Like .

Philip Pape 8:01

When we say unsafe , we also have to qualify and define what we mean by the word unsafe . To me , unsafe is more about the totality of the context , right Like if we're driving . If you said , is driving 65 miles an hour unsafe ? Well , it depends on the road conditions , the weather , your car , the driving experience . 65 miles an hour in a school zone is extremely unsafe , but on the Autobahn you're probably going to get honked at for going too slow , right ? So same thing applies to calories . In that the context really matters . In fact , 800 calories is not far from where a lot of people might hit when doing a rapid fat loss phase for two weeks with protein modified fast . Right , and it wouldn't be unsafe in that context . It'd be highly controlled , highly structured , exactly what they're intending to do . That's why I think it's important not to blanket statement anything .

Philip Pape 8:50

So when we talk about very low calorie diets and defining our terms , there's actually a term VLCD very , very low calories per day , I think . Or very low calorie diets , right , vlcds . And they are actually defined as 800 calories a day or less . But these are not like lifestyle diets . These aren't rapid fat loss phases . They are clinical interventions , typically under medical supervision , for people who have severe obesity or diabetes , and there's actually a lot of robust research on properly supervised ,

Metabolic adaptation vs. metabolic damage

Philip Pape 9:24

very low carb diets or low calorie diets , not carb Icalorie diets . When you look at those studies , we see rapid weight loss of about three to five pounds a week and a lot of the blood markers improve . Blood sugar , blood pressure , lipid profiles make sense because we know that there's a high correlation with reducing excess body fat .

Philip Pape 9:43

Notice that what I said in this these are properly supervised , clinical , very low carb , very low calorie diets , have somebody monitoring . They have high quality protein which is gonna preserve your lean mass . They have vitamin and mineral supplementation , regular checkups with the medical provider , and they're temporary no more than , say , 12 to 16 weeks , which to me is actually quite a long time for 800 calories . If you weren't in a medical situation , at most you might do it for two or three weeks and then they transition back to higher calories . So either way , you're recovering afterward , which again doesn't mean it's unsafe . No , for these people it's actually what they need to survive and live a thriving life again and have healthy blood markers so they don't die . That's the opposite of unsafe . Now life again and have healthy blood markers , so they don't die . That's the opposite of unsafe . Now do they have to do it that way ? I don't know . That's a whole different conversation .

Philip Pape 10:30

I think the problem comes when the commercial , highly marketed weight loss programs take a number like that and then they give you the food Optivia , anyone . They give you processed bars and shakes , they send it to your door , they tell you not to exercise and then they send you away for months at a time and like good luck . Well , we know how that ends . That ends with crash and burn and even if you lose the weight , you're going to gain it all back because you don't know how to sustain that right . And I'm sorry to pick on Optivea specifically , but it comes up time and time and time again Cl and time and time again , clients and students every day who I talk to have tried this in the past and I wish I had met them before they tried it . But hey , it's a good learning experience , if nothing else . Right , it puts everyone on a really low , sub-thousand calorie diet using pre-packaged foods . That's gross , I mean , I think that's gross . I don't want to live that way .

Philip Pape 11:22

You know what I did slim fast a long time ago when I was like 20 for maybe two months , hated it . It was miserable . Every time I knew I was going to have lunch I'm like , what am I doing ? I think I actually eventually snuck Chinese food with my slim fast , thinking that well , I'm still having the slim fast . Like , seriously , I think that's what I did because I was so craving more food and obviously , okay , look , there's a lot of problems with this approach . It's not like I'm telling you something that is surprise , but the big one is the one size fits all calorie target , regardless of body size , activity level , metabolic rate . And it ties to this topic because people will say the 1200 , the 1500 calories , the less than 2000 calories , whatever is , quote , unquote this or that for everybody . You just can't make statements like that . Again , 120 pounds versus 200 pounds , sedentary person versus active person , somebody lifting weights with lots of muscles , somebody who's who's sedentary , right , big differences . So that's the big one .

Philip Pape 12:19

The second one is that for the programs that push these things , sometimes the macros are all screwed up or the protein is low and I know there's a whole movement toward you know protein is dangerous or like stop protein maxing or proteins crowding out all this other stuff . Folks , we do not get enough protein on average in this country or in the world in general . Most people are far deficient just getting enough protein . We're not talking about 300 grams a day of protein . We're talking 0.7 to 1 gram per pound of your body weight . So if you're 150 pounds , that's no more than 150 grams of protein . It's not a massive amount of protein . And if you do it as a percentage of your diet , it's also not massive . It's like 15 , 20% , right , it's not that high . So if you're on an aggressive deficit , you have to have high protein by default . So as soon as you lose the connection between those two , you're going to have problems .

Philip Pape 13:08

And then the other thing here is that something like Optivia discourages exercise . I don't understand that and I'm not going to waste my time reading the Optivia and the Manjaro and the Terzepatide or Wegovi and all that , where people are giving these things or maybe they get them themselves without any guidance on lifestyle , and they're not lifting weights and they lose muscle as a result , right , not because of the drugs , but because of the aggressive deficits , the low protein and all of that , and it leads to worse body composition outcomes , which is not what we're trying to do right Now . The programs that give you foods that are prepackaged I mean just that's a whole separate issue as well . You know , being dependent on these , it's really quite the racket , isn't it Like ? Just , instead of learning how to structure your own nutrition , just make your own food . Or even if you want to buy prepared food from like a service and choose the foods that meet your goals , that's fine . It's this idea of them sending it to you and locking you into that . So now compare all that to what we talked about on width to weight , which is an evidence-based approach where we calculate your energy needs , we make sure you have enough protein , we emphasize resistance training consistently and , most of all , we use flexibility with your food , with really , really the whole process

Biofeedback trumps arbitrary numbers

Philip Pape 14:27

is got a lot of adaptability and flexibility built in , because it should conform to your constraints and your life , your ability to adhere and maintain beyond just a short-term dieting phase and actually be able to eat for life . And so this is why context matters so much in nutrition and why I love to help people get to that next step of .

Philip Pape 14:52

Okay , I've listened to the podcast , or I listened to a bunch of physique . You know fitness podcasts and I know the science and I know the general idea here . But how do I do that for myself , right ? So that's why I created Physique University . We don't use arbitrary numbers . We actually help you determine your actual needs based on your body size , activity level , biofeedback . We then work backward to create the plan that has the right aggressiveness for you .

Philip Pape 15:18

So , again , it's not just here are my calories and macros . It's what is your goal ? Is your goal moderate fat loss or body recomposition ? Is it a bit more aggressive ? Are you actually trying to build muscle ? And then , what is the right lever ? And then , beyond that , should you be eating the same calories every day or should you cycle ? Should you have more on the weekends , right ? All that's what I'm talking about when it comes to making it fit your life , so that the numbers are the same , but the way that it's structured might vary drastically , right ? So it's not just . Here's a template . So , anyway , if you're looking for something like that , check out Physique U , use the special link in the show notes . I'm going to keep mentioning this because that link is going to give you a special bonus . You're going to get a free nutrition plan from me and that's going to unlock an accelerator that'll help you get even faster to your goal . Not quick fix , fast , but efficiently fast to your goal to lose fat , to build muscle , for your situation .

Philip Pape 16:14

So let's address the elephant in the room metabolic adaptation . Right , you've heard me talk about this , or , if you're new to the show , I want to contrast metabolic adaptation with terms like metabolic damage or starvation mode that are used by people to claim that either aggressive deficits are harmful and permanently so , or that you are permanently harmed because of something you did in the past , and I'm sorry , but we're going to have to fix that , and here's my special protocol to do it . The truth is more nuanced and also more empowering , I would say , in that metabolic adaptation look at the word adapt . Adapt is something that is flexible , right , it can adapt one way and then it could adapt back . It's a real thing . It's a real phenomenon where , when you eat less , your metabolic rate decreases beyond what you'd expect , just from losing weight . So if you're losing weight , if you're in a deficit , the fact that you weigh less is going to burn fewer calories , yes , but beyond that , your metabolism goes down due to what's called metabolic adaptation . It's kind of a protective mechanism . It's an efficiency mechanism .

Philip Pape 17:23

We've talked about the biggest loser study and I know there's a big Netflix documentary about it I haven't seen it yet but they had massive metabolic adaptation . It persisted years later and it's recoverable , but it's recoverable only on a similar timeline as it was adapted in general right . And in that study they had extreme deficits combined with excessive cardio , combined with inadequate protein . They had muscle loss and they had metabolic adaptation . So part of their metabolic decline became permanent , not because of adaptation , but because of things like muscle loss that they're going to have to build back .

Philip Pape 17:58

When we talk about just run of the mill metabolic adaptation , this is driven by a few different things . Now , if you're losing lean mass , to me that is not a source of metabolic adaptation . That is a source of burning fewer calories due to having less muscle . That's different . But the hormonal changes that come in from metabolic adaptation , like a decrease in thyroid and reproductive hormones , those are real and they cause you to burn fewer calories and that's normal .

Philip Pape 18:27

And the more aggressive you go , the more that's gonna happen , to the point where you're also getting the lean mass loss . You're getting the hunger that gets ramped up . You're getting the fancy terms like hyperphagia , which is just massive hunger , but if you're in the right window , you're gonna have some metabolic adaptation . But you're going to have some metabolic adaptation , but you're also going to preserve your muscle by eating protein , by training , and the adaptation is much less severe and more , I'll say , reversible in a short period . That's the way I'm going to put it . It's always reversible . It depends on how aggressively you did the diet .

Philip Pape 18:58

And again , this connects to this topic of like 800 calories or whatever . So I guess the silver lining of that is that an aggressive deficit , in some ways it's reversible . And because the time is short , the reversibility is also short . But if you go aggressive for a long time , then that's where the problem comes in . You're not gonna permanently damage your metabolism , which is the thing that could sensationalize . Okay , I hope all that made sense . So I like to think like an engineer .

Philip Pape 19:28

Right , every diet involves trade-offs between three main factors the speed of your results , the sustainability of the process and , I'll say , preserving your metabolism , that's . I'm not talking about the cost schedule , quality triangle , the iron triangle , fat loss that's a different thing that I talked about in another episode . This is more of a the three things that are going to get impacted the most when you do a diet and how you can optimize . So you can optimize for speed and you can go very aggressive with a deficit , but you're going to sacrifice sustainability and that's where you have to keep the time short . Right , you're going to increase the risk of muscle loss . If you don't , you're going to increase the risk of severe metabolic adaptation . So that's one thing . You could also optimize for how sustainable it is , how much you can adhere to it , by making it more conservative , but of course , your progress is going to be slow . And then you can optimize for preserving your metabolism by going at a reasonable level of aggressiveness , but also having diet breaks and refeeds ,

Building sustainable results, not false rules

Philip Pape 20:30

and that's going to extend your timeline . Extend your timeline . You're not actually on the net increasing your metabolism , you're just taking breaks along the way and it's going to take longer , but it's going to feel more sustainable while still being somewhat aggressive , if that makes sense .

Philip Pape 20:44

So the key here is to understand these trade-offs and then to choose intentionally , consciously , not accidentally , falling into usually what's an extreme approach because someone said you know these are the amount of calories you should or shouldn't go above or below . So let's talk about biofeedback for a second , because that's another thing I had in my notes here . That is extremely helpful as a guide . All right , we fixate a lot on numbers and , when it comes down to it , numbers like your expenditure , like how many calories you have to hit , like your macros , are just starting to scratch the surface , right ? What's really below all of that is what's in your body . It's your biofeedback , it's the constant information that you get about whether your approach is actually working or you're pushing too hard .

Philip Pape 21:33

Now , it's hard for many people to read those signals when they first do this , because they're so screwed up , they're so misaligned and miscalibrated from years of doing this the wrong way , and that's okay . When you start to do things intentionally , you also start to regulate your biofeedback signals . Your energy levels , your sleep quality , your strength in the gym , your recovery , your hunger , your mood all of that starts to get more regulated and then therefore more trustworthy . So it's kind of a chicken and egg , right . So that's why it helps to not be pushing anything too hard initially , to not be in a diet and to let things regulate while you're improving your sustainability part of the equation and improving your food quality and things like that , and then you can challenge yourself . And then , once you challenge yourself with something like a diet , the goal is not to feel miserable . Right , we don't want to be miserable , and so the warning signals will be there in addition to the numbers .

Philip Pape 22:29

The numbers are one thing , but if I say , go and eat 800 calories and you do it and you actually feel great during the process , who am I to tell you that that's unsafe or too low ? But if I tell you to eat 1500 calories for a diet and you're you know you normally burn 3000 calories chances are you're going to get fatigued from that pretty quickly . You're going to have trouble sleeping , you're going to have potentially a loss in your strength and muscle . You might you might be in a bad mood , you might get hangry or actually lose hunger , you might lose hair . I mean I don't know . There's going to be a lot that happens in women . There's a lot of hormonal impacts , right with not only thyroid but , you know , menstrual cycle . I mean everything .

Philip Pape 23:06

So when you get that kind of biofeedback , that indicates you're pushing beyond what your body can handle sustainably , and that's where it gets into the word potentially unsafe . You know again , what does safe mean ? That's questionable . Now , the beauty of biofeedback is it is completely personalized to you , by definition . Right , the more petite woman eating 1200 calories , she might have excellent biofeedback , being in this moderate deficit , and the weight just comes off , no problem done with , the diet moves out . But then you got that bigger man , let's say the 200 pound man . He's eating 1800 calories . My show warning size For me . My biofeedback can fluctuate , and so that's another , more advanced way to handle those signals , in that you can push sometimes and pull back other times . So , regardless of your calorie target , two factors are critical that we've mentioned already no-transcript , very low calories .

Philip Pape 24:23

Maintaining those priorities of training and protein is going to dramatically improve your results and reduce the negative consequences that come from aggressive dieting . All right . So I had some other things . I had some other things to talk about it , but I think we're going long winded here .

Philip Pape 24:39

My , my message to you if you're considering a very aggressive approach , obviously if you have underlying health conditions , if you're taking medication , something like that , working with a health provider , right , that's outside my scope , that's medical . If you're considering it for something like rapid fat loss and I get people come to me all the time . Hey , I want to follow your rapid fat loss protocol and I'll say , okay , are you training ? Are you tracking ? Are you eating enough protein ? Do you have a good body image ? Do you have a good relationship with food ? If any of these answers are no , sorry , don't do rapid fat loss , because that's just recipe for disaster , you know , is your stress high ? Is your right sleep bad ? All that stuff has to be dialed in right . So if you're considering a very aggressive approach , it is perfectly safe , if it's right for you , if it's controlled and structured and if your biofeedback is solid for the duration of that deficit .

Philip Pape 25:29

So I want to leave you with what I consider the most important insight from today , and that is that the fitness industry , they've conditioned us to think in absolutes , and maybe conditions not the right word , I mean , I think it is , but it could just be that they have , you know , blasted the message that there are dichotomies , that there are false dichotomies . I should say , you know , safe versus unsafe , you see it all the time Fear mongering all the time , good versus bad , right versus wrong . But your body doesn't operate that way . Right , it has context , it has constraints . So it's not whether X number of calories is inherently safe or unsafe . It's whether a specific target makes sense for your unique combination of all the things your body size , your activity , your goals , your life circumstances .

Philip Pape 26:13

So , instead of asking what should everyone do which is , by the way , a very common question to podcasters is what ? What is the answer to this ? What should I do here , without the context ? It's what makes sense for me right now . Okay , what makes sense for me right now ? In fact , I was just thinking in our , our Facebook group , which you can join for free anytime , which , in which Facebook group , we actually have an Ask Philip thread that I do once a month , and the whole point of that thread is for you to ask the question what makes sense for me right now , right .

Philip Pape 26:42

And then you stop being a victim of arbitrary rules Yep , I said it trigger word victim and you start being the intelligent I was going to say designer , but isn't that referred to a creationism and stuff , the engineer of your own approach , right ? And this is the mind-blowing shift in your brain that I think separates people who actually get this thing , that make it last , that sustain those results that they're walking around one year , five years , 10 years from now , having lost the fat , having improved their body composition and they're living an enjoyable life from those who bounce and yo-yo between the extreme approaches , hoping that the next solution is going to work for them . So the next time you hear someone online say that a specific calorie number is universally safe or unsafe , number one , unfollow them . And then number two , you'll know that you're missing the bigger picture , or that they're missing the bigger picture , I should say , because of everything we talked about today . Right , and you know better . You know better . So , instead of searching for the magic number , focus on developing skills , skills the skills to understand your energy needs , your biofeedback structure , your nutrition for your goals . Make informed trade-offs based on what matters most to you right now , which only you know , only you know , and if you need to share it with someone else to get some accountability and some help , that's what we're here for . That is how you make it sustainable . That is how you achieve your goals .

Philip Pape 28:04

And look , if you want to connect with others who understand this . You don't want to join Physique University yet . You're not ready to take the plunge there and accelerate your results to that level . You can still join our free Facebook community . I that level , you can still join our free Facebook community . I already mentioned it once . You can search for it on Facebook or click the link in the show notes , and that is where we share experiences , we ask questions , we support each other without judgment , without oversimplified advice that you're going to find everywhere else . All right , until next time , keep using your wits lifting those weights and remember your physique is built through evidence , not arbitrary rules . This is Philip Pape , and you've been listening to Wits and Weights . Talk to you next time .