The theory is that we have an essential amount of body fat. Kind of a minimum level allowed in the tank.
For men this amount is roughly 5% of body weight, for women it’s closer to 13%.
Admittedly I have not explored the science behind these numbers, but for the purpose of this blog post, let’s assume they are correct.
(I also find basing the essential amount as a percentage of total body weight as opposed to a percentage of leanbody mass to be odd…but I digress.)
So for me, 5% is essential.
Then as a ‘safety cushion’ let’s assume enough fat to provide 2 weeks worth of energy should I need it.
That’s about 8 pound of fat ( 28,000 back up Calories at my disposal – more than enough)
That means that at my LBM (roughly 150-155 pounds…we’ll say 152.5) I should have about 8 pounds of essential body fat.
(152.5 / 0.95 = 160.5 160.5 – 152.5 = 8 pounds)
Now adding on my 2 week buffer I have 16 pounds body fat, or a weight of about 168 pounds.
So at my height and given LBM I know that I really wouldn’t want to weigh any less than about 162 pounds, but have no reason to weigh more than 168 pounds.
Anything extra is just excess weight.
Since I don’t see any reason I would be without food for more than 2 weeks, there is no reason for me to carry any more than 16 pounds of body fat.
And this is where the term ‘excess’ comes from
Excess – more than or above what is necessary, usual, or specified
I think this is something we have to remember when we are losing weight. We’re getting rid of the Excess – It’s kind of like housecleaning for your body.
It’s weight you don’t need. And that you have no use for. And while it’s a chore to get rid of it, it’s a freeing feeling to do so.
Just like de-junking your house or apartment – it’s a lot of work, but it feels great once it’s done….and really, you don’t need most of that stuff 
BP
Brad how tall are you? 155 lbs. of LBM seems pretty low.
I’m 6′ and 188 lbs. and have around 160 lbs. of LBM. and you’re clearly more muscular than I am.
Excess body fat is a good way to think about it. When you think about “losing weight” your first instinct is to one day “find it” again. I think people would be better off basing their excess fat loss goals on body fat percentage as opposed to the actual weight. Having leavn muscle will throw pounds on the scale but its nothing to be concerned about. Here is a link to some calculators for body fat as well as the charts showing what is healthy and what is overwieght if anyone is intrested.
http://www.liftingheavy.com/height-weight-tables.html
Hi Rick,
5’10
So by rules of sevens I am slightly more muscular than you would be at my height (Roughly 146)
B
What is the rule of 7′s?
Hi Brad,
How do you estimate your LBM?
Andrey
amazing that when one gets gets lean enough to not have excess fat they are deemed too skinny. america is so used to fatness that they feel excess is the norm and even healthy looking. my body composition is similar to yours. i probably hover around 10% bf and am sick pf being told i am too skinny when technically my bmi says i am overweight. what is it people.
personally i would love to have more muscle mass and that is a constant struggle but i am not gonna put on fat so i don’t look skinny through america’s fat tinted glasses.
Hi Andrea and BigJay,
Rule of 7′s is how you can estimate lean body mass based on height. It’s not perfect, but it will suffice when you don’t have things like a BodPod or Dexa available.
B
Brad,
Could you please provide a link or reference to that rule? Google doesn’t know about it.
Andrey
Andrey,
Rule of 7′s is explained in the Adonis Effect.
B
Interesting calculations. It’s good to calculate this, because you will have some specific goal where you know you need to get. Also, once you get over this goal, in your case it’S 168 pounds, you know that you either take steroids or it’s just fat.
Great post Brad. Looking forward to reading more stuff from you,
Greg
Hi Brad, i buy your book and i will do my first fast in 4 days, great reading there. I have a little question regarding weight lost, in fact fat lost. Im not overweight, I can see my 4 pack, but i need to reveal my lower abs, i did that for 3 months with diet and workout, i just eat pretty clean, chicken, tuna, fish, meat, and veggies, now my question is if you can still get very ripped, just having a caloric deficit and eating whatever i want, and doing weight exercises? The mainly concern is that i prefer to eat less high caloric foods like pizza, or pasta, burgers, etc, that just chicken, meat and tuna, and get bored of that food, in fact i prefer to eat ALL my calories ( still having a deficit) in just one meal, than eat all day long just chicken, meat and veggies. Thanks for the reply.
Hi & THX Brad
For medical reasons I workout 2x aday 6:30am 5 pm when do I eat?
It really doesn’t matter….if possible after your workout but only because i find eating too much before your workout can sometimes be painful.
Hi Brad,
Please be honest!
I am thinking of buying your book eat stop eat but I am really scared of betrayal.
I have purchased so many items via clickbank through recommendations of existing purchase. Claiming how each of their diet is different and not a diet yet every single one has been the same allowable foods ie protein carbohydrates.
Your claim is however different as it revolves around fasting but are your promises right which say you can eat any food you like?
You can eat any food you eat, just not too much of it.
B
Thankyou Brad
You can count me in then!