Peter Attia· MD
uh 50 to 70% is a relatively accurate representation for me it's probably about 55 to 60% of my total daily energy expenditure because I do train like two two and a half hours a day so that is a significant contributor so we have that then we have what's called TEF which is the thermic effect of food or Diet induced thermogenesis and this is anywhere from 5 to 10% of your total daily energy expenditure for most people very very hard to measure um usually it's expressed in terms of you know calories per minute uh because they're only looking at it in the short term and when we do studies of total daily energy expenditure I mean usually what they're doing is using a constant for TEF they're they're making an assumption because it's just so hard to measure unless you're just measuring that over like the course of a couple of hours or maybe a day at most but we feel relatively confident based on the the studies out there that it's about 5 to 10% of your total daily energy expenditure so not a not a big contributor but still but it also seems to be macronutrient dependent correct it is it is so that's one of the things we'll come back to that when we get to yeah yeah and then if we look at kind of the last component we have our physical activity and this encompasses all physical activity so people hear this and they think exercise but actually the biggest for a lot of people their biggest component of physical activity is actually what's called neat which is non-exercise activity thermogenesis and that is something that's actually extremely modifiable and and we see it in terms of one people who are obese resistant what we what we term obese resistant they tend to fidget a lot they tend to move a lot I was like this as a as a kid I still am uh whereas people who are obese prone tend to have very low neat and in fact there was a study done by liel in 1995 where they overfed people by I want to say a th000 calories per day and they determined this they they looked at their total energy expenditure and a metabolic Ward so very accurate and then they took that number and added a thousand calories on top of it and they looked at how much weight people gained somebody some people gained more than they expected one person did not even have significant weight gain and what they found was this individual's neat their spontaneous physical activity went up so much it just compensated for that for that extra calories and so I think this is what people really don't understand as well Is We I want to be very purposeful about how we Define neat because when it comes to neat versus exercise exercise is purposeful so something I'll hear a lot is well I'm going to go do a walk and get my knat up no you're doing exercise I'm maybe I'm being a little bit pedantic but it's important because neat is what I'm talking about fidgeting it's what like with my like not right now because now I'm thinking about it but like I'm waving my hands around I'm kind of like you know moving from one foot to the next you know I've seen Peter that like you kind of move your fingers and you'll kind of you know twitch your neck that all that stuff even though it seems like nothing thousands of those movements over the course of a day actually add up so then I have people say well I'm just going to like tap my foot you know to to get knat up or fidget well guess what's going to happen whenever you try to do something that all also requires your brain you're going to stop doing that because you actually can't really do two things at once in terms of like thinking about it so This truly is spontaneous energy expenditure and appears to be modifiable by about 5 to 600 calories per day and we do see this with overfeeding and underfeeding so people who are and we'll get into talking about metabolic adaptation and how this affects things but people who lose like 10% of their body weight they've seen up to a 500 calorie reduction in neat so that's a big portion of it and then obviously you have your purposeful exercise so if we look at energy out or energy in metabolizable energy energy out BMR TEF neat and exercise I'm simplifying this equation a little bit but that's essentially it um so when people if people want to invalidate energy balance what I always say is listen you ate those carbons something must happen to them you you cannot just they don't flutter off into Oblivion and you don't create them out of nothing right something has to happen to them and we have a lot of metabolic Tracer studies to pretty much know what happens to them I think the confusion becomes well I tracked my my calories I ate in a 500 calorie deficit and I didn't lose weight first off if we look at where these mistakes come in people weigh themselves sporadically and if you only weighed yourself once a week I would say it's virtually meaningless um when we are trying to get data on people we're very regimented with how we do it so it's you