Myth or Fact? Simple Math: 3500 calories = one pound? Eat

Options
So many folks have posted information on MFP about whether to eat their exercise calories or not, and I provided my answer but never previously provided the WHY behind my approach. I hope this information helps answer that question in part, but the other question it addresses is whether the simple "calories in versus calories out" and "3500 calories = one pound" tenets are universally accurate.

Many others, myself included, have touted the 3500 calories = one pound calculation, which is the accepted general rule, but out of good faith, I am adding one big caveat. My guidance is based on recent findings published in the International Journal of Obesity (http://www.nature.com/ijo/journal/v32/n3/abs/0803720a.html).

The short of this new (2010) research teaches us that while 3500 calories to lose a pound has always been the rule of thumb, this figure stems from research which (incorrectly) assumed that all the weight lost would be adipose tissue (which would be ideal, of course).

So, first of all, yes one pound of FAT = 3500 calories.

Here's where the caveat comes in. Because lean body mass is lost along with body fat, researchers now know the 3500 calorie figure is, for many, an oversimplification. The amount of lean body mass you will lose is based on your initial body fat level and size of your daily calorie deficit. Lean people tend to lose more lean body mass and retain more fat. Obese/overweight individuals tend to lose more body fat and retain more lean tissue (this explains why obese people can tolerate extremely low calorie diets better than already lean people, and why lean folks (close to their goal weights) have a devil of a time losing the last few pounds and need to be extra aware that they need to avoid an ultra low calorie approach to losing those pounds). Very aggressive low calorie diets erode lean body mass to a greater degree than more conservative diets. Whether you are losing lean or fat, tells you what is the required energy deficit per unit of weight loss is for you.

The metabolizable energy in fat is different than the metabolizable eneregy in muscle tissue. A pound of muscle is not 3500 calories. A pound of muscle yields about 600 calories. If you lose lean body mass then you lose more weight than if you lose fat. If you create a 3500 calorie deficit in one week and you lose 100% body fat, you will lose one pound. BUT if you create a 3500 calorie weekly deficit and as a result of that deficit, lose 100% muscle, you would lose approximately 6 pounds of body weight (a very bad thing).

If you have a high initial body fat percentage, then you are going to lose more fat relative to lean, so you will need a larger deficit to lose the same amount of weight as compared to a lean person. That means that eating at a lower calorie level will work better for you than for a relatively lean individual.

Creating a calorie deficit once at the beginning of a diet (e.g., a 750 calorie deficit per day) and maintaining that same caloric intake for the duration of the diet and after major weight loss fails to account for how your body decreases energy expenditure with reduced body weight. Your dietary needs will change as you lose weight. As you get lighter, your daily caloric need will diminish as will your body's ability to tolerate a too low calorie intake (consequence? you'll begin to lose more lean and hang onto the fat, thereby getting lighter but "fatter").

Weight loss typically slows down over time for a prescribed constant diet (we call this a "plateau"). This is either due to the decreased metabolism mentioned above, or a relaxing of the diet compliance, or both (most of us can't stick to excessive calorie reductions for long). Progressive resistance training and adequate caloric intake can modify the proportion of weight lost from body fat vs lean tissue.

So ... should you throw out the old calorie formulas? Not necessarily. You can still use the standard calorie formulas to figure out how much you should eat, and you can use a 500-1000 calorie per day deficit (below maintenance) as a generic guideline to figure where to set your calories to lose one or two pounds per week respectively (at least on paper anyway).

Even better however, you could use this info to fine tune your caloric deficit using a percentage method and also base your deficit on your starting body fat level, to get a much more personalized and effective approach:
15-20% below maintenance calories = conservative deficit
20-25% below maintenance calories = moderate deficit
25-30% below maintenance calories = aggressive deficit
31-40% below maintenance calories = very aggressive deficit (risky)
50%+ below maintenance calories = semi starvation/starvation (potentially dangerous and unhealthy)

(Note: According to exercise physiologists Katch & Mcardle, the average female between the ages of 23 and 50 has a maintenance level of about 2000-2100 calories per day and the average male about 2700-2900 calories per day)

A conservative deficit of around 15-20% below maintenance is often appropriate, especially for non-obese individuals.

In a nutshell, Dr. Hall’s research tells us that there are big differences between lean and overweight people in how many calories they can or should cut. If you are obese/significantly overweight, dramatic deficits will still result in a high (and desirable) ratio of fat loss to lean loss. If you are lighter, then you must pay more attention to being sure your calorie consumption doesn't drop too low. Be aware of where you are on this curve, and adjust as you make progress toward your healthy weight and body composition goal.

:)
«13456711

Replies

  • MyaPapaya75
    MyaPapaya75 Posts: 3,143 Member
    Options
    very nice post ty
  • SiltyPigeon
    SiltyPigeon Posts: 920 Member
    Options
    Thank you so much! This was a beautifully written post! Very helpful information!
  • TrainerRobin
    TrainerRobin Posts: 509 Member
    Options
    Thank you so much! This was a beautifully written post! Very helpful information!

    Thanks ladies. Just hoping it'll be helpful to some of you!

    :)
  • NightOwl1
    NightOwl1 Posts: 881 Member
    Options
    Awesome post. I hope Mike (the creator) reads this and adds this to the must read posts. I know I'm going to link to it often. This is why I've continued to reduce my weight loss goal as I lose weight. Now I'm at 1/2 pound, which is a 250 calorie deficit. I'm also doing constant strength training in the hopes of not losing any lean muscle mass.
  • TrainerRobin
    TrainerRobin Posts: 509 Member
    Options
    Awesome post. I hope Mike (the creator) reads this and adds this to the must read posts. I know I'm going to link to it often. This is why I've continued to reduce my weight loss goal as I lose weight. Now I'm at 1/2 pound, which is a 250 calorie deficit. I'm also doing constant strength training in the hopes of not losing any lean muscle mass.

    Perfect approach. For folks like you who are within a healthy weight range, you've nailed it. Your calorie deficit can't be dramatic like it can be for obese folks and the resistance training is a MUST (as it is for everyone!). You've got it!!

    Congrats on your success. Nicely done!! :)
  • BRVERDUZ
    Options
    Thank you..great post
  • watkinsc
    watkinsc Posts: 177 Member
    Options
    Wow! What a great piece of information... Thank you so much! =)
  • kateopotato
    kateopotato Posts: 215 Member
    Options
    Very informative! Good read! Thanks
  • ce_fit
    ce_fit Posts: 299 Member
    Options
    Very well written and appears to be well researched. Thank-you
  • MobiusMan
    MobiusMan Posts: 385 Member
    Options
    Really good post Robin. Likewise from a purely thermo-chemical standpoint. the ignition of 1 pound of fat would indeed yield the energy (approximately) required to raise 3500 Kilos of water 1 degree Celsius at one standard atmospheric pressure (air pressure at sea level)
  • elid
    elid Posts: 209 Member
    Options
    Very good, thank you. Great motivation for me to keep up with strength training.
  • WTFitness
    WTFitness Posts: 77 Member
    Options
    Awesome post! Thanks a lot for the info :)
  • mirahonthawall
    mirahonthawall Posts: 236 Member
    Options
    Good to know! Thanks!
  • Canonoch
    Canonoch Posts: 120
    Options
    actually very interesting
  • TrainerRobin
    TrainerRobin Posts: 509 Member
    Options
    Really good post Robin. Likewise from a purely thermo-chemical standpoint. the ignition of 1 pound of fat would indeed yield the energy (approximately) required to raise 3500 Kilos of water 1 degree Celsius at one standard atmospheric pressure (air pressure at sea level)

    You've got it! That's exactly right!!!

    And all of this makes sense when you think about it.

    We all know that a pound of fat is PHYSICALLY larger than a pound of lean.

    And we all know how concentrated fat calories are (just a tablespoon of the stuff packs 120 calories ... much more than a tablespoon of lean protein).

    So it follows that a pound of fat would pack far more ENERGY as you noted (calories to the rest of the world) than a pound of lean.

    I'm always thrilled when researchers provide accurate info to us that helps us make our journeys to a healthier body weight/composition less frustrating and more fruitful!

    :)
  • 321Detonate
    Options
    Fascinating read and very articulate. This is easily one of the best posts I've read on these forums. Thank you for taking the time to write it!
  • Teran0612
    Teran0612 Posts: 263
    Options
    Great post!!! Thanks so much!! :)
  • TrainerRobin
    TrainerRobin Posts: 509 Member
    Options
    Fascinating read and very articulate. This is easily one of the best posts I've read on these forums. Thank you for taking the time to write it!

    You are very welcome.
  • leslielove
    leslielove Posts: 251 Member
    Options
    That's amazing.

    How would the information you presented translate for someone who is not far out of weight range but has significantly higher body fat than desired? I'm 5'3, 149 pounds, and roughly 28% body fat. I'm currently running a 500 calorie deficit plus around 300 calories a day of exercise (which I do eat back for the most part) and my MFP calculated BMR is ~1760. I'm following the MFP recommended macronutrient ratios - not sure if that's of much consequence but I thought I'd throw it out there.

    What am I looking at, calorie and macronutrient wise, for optimum weight loss? I'm looking to get down to 135, ideally 130 if I can maintain it and somewhere in the low 20's for body fat. I think, I've never been that small so I'm guessing on both fronts but I know I want to lose both weight and fat. Help!

    Robin, you rock :)
  • RMinVA
    RMinVA Posts: 1,085 Member
    Options
    Robin - Second post of yours that I have read that reiterates what I know about weight loss. Only you said it/explained it much better than I ever could!! Thank you SO much for sharing.