My Morbidly Obese FIRE

Physician on FIRE may not have invented FIRE (Financial Independence, Retire Early)  but he certainly introduced it to me.  Before his blog I was saving and investing without a particular goal in mind.  Bogleheads and White Coat Investor taught me all about living below my means, investing early and often, diversification and tax planning.  It wasn’t until Physician on FIRE that it occurred to me that becoming wealthy might mean early retirement.  I like my job and the thought of walking away early had never occurred to me.

Financial independence means different things to different people.  One person may consider financial independence having enough money to afford a lifetime supply of ramen noodles in their studio apartment.  Someone else might consider independence having a lifetime supply of jet fuel to fly to their private island.  Since personal finance is personal, it is up to you to decide what financial independence means to you.

Here’s a look at what different levels of financial independence means to me.

Lean vs Fat

Two recently popularized terms in the FIRE community are lean FIRE and fat FIRE.

People in the lean FIRE camp are willing to sacrifice their standard of living to retire early. Think biking 5 miles to the grocery store to use the coupons you cut out sitting in your non-air conditioned 1 bedroom condo.

People in the fat FIRE camp aren’t willing to make those sacrifices. They still want to travel, go out to restaurants and drive to the store.  They’re not sailing their yacht to their private island, but they’re also not wearing their winter coat indoors to avoid turning on the heat.

lean fat obese
Exponential growth

What’s your BMI?

Before we go any further, I need to know your BMI.  I’m not talking about your waistline.  I’m talking about your checkbook.  Your Banked Money Index is a multiple of annual expenses you currently have saved.  If you have 5 years worth of expenses saved up, you have a BMI of 5.

I’m a very conservative planner and not a big fan of biking my groceries home so my minimum retirement goal is a BMI of 25.

Lean FIRE (BMI = 25)

Retirement Savings = $3,125,000

4% Withdrawal = $125,000/year

lean FIRE
Lean, mean saving machine

With 25 years of expenses saved I would begin to contemplate early retirement.  At a minimum it would change my thoughts about work.  I would begin by cutting out the parts of my job I don’t like.  If you have ever worked shift work you know that means exactly one thing – night shifts.

There’s a reason working night shifts is an independent risk factor for cancer and cardiovascular disease.  I haven’t had a consistent bedtime since 2008.  Even on my days off it is rare for me to sleep more than 5 or 6 hours in a row.  Night shifts destroy all motivation to exercise.  I’ve never once got off a rough night shift and craved a salad.

I will likely continue easy work-from-home side hustles, but it would be in exchange for further cutting back day shifts at the hospital.

I will still max out taxable accounts but my focus will be on padding the kids’ 529s.  I certainly won’t retire if any of my 3 junior hustlers aren’t set for college.

Fat FIRE (BMI = 33)

Retirement Savings = $4,125,000

4% Withdrawal = $165,000/year

fat FIRE
My wallet isn’t fat – it’s just big boned.

At this point I would no longer be working for financial reasons. It would clearly be because I like interacting with patients and coworkers. I would eliminate not only night shifts but also weekends and holidays. No longer would I miss Christmas mornings, Thanksgiving dinners or Fourth of July fireworks. My wife wouldn’t have to plan our lives around my weekends off because they’d all be off.

I would likely take extended vacations or travel assignments like international medical volunteer work.

I would even consider (gasp!) stopping all my side hustles and just enjoy having more free time.

Morbidly Obese FIRE (BMI = 50)

Retirement Savings = $6,250,000

4% Withdrawal = $250,000/year

morbidly obese FIRE
Rolls on rolls on rolls.

At this point I would have so many rolls (of cash) that a bariatric surgeon would have to trim them off me.

I would have so many rolls that I couldn’t remember the last time I could look down and see my own…..wallet. I would have to buy my money belts at the big and tall store.

Like many people who become morbidly obese I will need to examine the psychology of my behavior. Why am I still packing on the pounds, dollars and euros? Is it even healthy to carry that much extra weight in your wallet?

If I’m still working clinically it is only because I still take personal enjoyment from helping the sick and injured. I will try to find volunteer work that gives me equal satisfaction.

I would also consider starting new business ventures, comforted by the fact that even if I fail miserably I will still have plenty of money to live off of.  People need new challenges so they can continue to grow and develop.  It’s easier to take risks when you have a 6 million dollar safety net.

How Fat Is Your FIRE?

Everyone has a different vision for their retirement.  If you hate your job and you are comfortable taking risks you might be willing to lean FIRE with a BMI of 15.  If you love your job and hate risk, you might still be working with a BMI of 60.  FIRE is less about retirement and more about living life on your own terms.

These numbers are moving targets but I would suggest sitting down and figuring out what your lean, fat and morbidly obese FIRE numbers are.  Next imagine how achieving those different numbers would change your day-to-day routine.  You will find those changes to be much more motivating than an arbitrary number on the page.

What do you think?  Are you aiming for lean, fat or morbidly obese FIRE?  Do you think these numbers are too risky or too conservative?  Share your thoughts and comments below.

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33 thoughts on “My Morbidly Obese FIRE

  1. I think by your definition my goal has been lean FIRE at 125k/yr. Studies have shown that happiness peaks at around 90k/yr so figure that is a nice buffer to have. I think I am going to work regardless of what FIRE I achieve until my daughter enters college (another 6 yrs) and even then might go down to minimum hours to qualify part time health benefits as that is the biggest unknown for me in terms of potential expense.


    1. 125k is my current annual spending. I don’t think I would increase my spending if I achieve morbidly obese FIRE. It just provides a bigger safety net if my math is wrong. Money can’t buy happiness but it can lease you security.


      1. My current spending is 125k after tax. That provides a very cushy lifestyle feeding, clothing and traveling with 5 people in a house that is too big to justify. The specific numbers in the post are less important than the different BMIs and how that can impact the decisions you make.


  2. I love this idea of different levels of FIRE. There is a lot of risk built into the “lean fire” model. If a couple of your assumptions are wrong or the market does something unexpected you could get into trouble. I think I’ll want a little more insulation to be comfortable.


    1. It also factors in your job satisfaction. If you despise your job lean FIRE sounds like a great deal. If you love your job you may still be plugging along after fat FIRE. Like body types, retirement comes in all shapes and sizes.


  3. I love this concept as well. Although less money will be spent on transportation to and from work, unneeded insurance at that point (life, disability, etc.) the one big issue for me when calculating this number is health insurance. I truly don’t know what to expect and it weighs on me heavily during these discussions. With premiums being quite high (and likely rising) and an increasing age as we reach FIRE, this is a huge wrench in the equation. I really don’t know how to calculate the cost of insurance at my time of FI. This means finding a situation that offers insurance (aka job), having a lucrative side hustle/business or fat/obese FIRE in order to cover these premiums (Turning it into just an average overweight American FIRE). At this point, I’m not FI and am just staying the course, but I think that ‘yearly expenses’ is very difficult to calculate unless you are already paying these premiums and are budgeting for these expenses. Even if you are paying premiums/budgeting for these, I have no idea what to expect in ten years (universal healthcare or huge premium increases, neither, both?). Furthermore, we can’t predict the future with regards to our health. If one of us has an unfortunate medical condition, premiums and out of pocket expenses will likely rise. I initially set a date for FI in the not so distant future, but have pulled back on it a bit. I love the FI concept more than the RE part and will just let it play out.


    1. I too am more interested in FI than RE. I like my day job and I think I’m pretty good at it. I don’t have a solution to healthcare in early retirement other than forking over the cash. Part of me suspects a single payer healthcare system in the next 10-20 years. (Hopefully after achieving morbidly obese FIRE). 😉


  4. The BMI concept is fun!
    I am in the lean FIRE camp and aim for retirement savings of $500,000, but will probably not RE. If I were fat FI I would add a cat shelter to my life. At obese FI I would… have a big and staffed cat shelter.


    1. FIRE is definitely not an all-or-none thing. You may aim for fat FIRE and end up lean. You may think you’re on track for lean FIRE and end up morbidly obese! A properly timed bull market can blow up your BMI. Think of all the cat nip you could buy!


  5. By your definition I am morbidly obese now. I used these types of numbers to decide to quit OB. This decision really improved my life style. Although I am still working I am not up at night and no longer work on weekends or holidays. I too am concerned about health insurance. No one who understands this issue can feel confident about this area at the moment. I just took a part time job with insurance because of the uncertainty of it. I have thought for years the individual market would improve but every year the prices increase and the coverage declines.


    1. Isn’t it interesting that there is no true number that makes us feel 100% secure? Even amongst doctors (who should be best equipped to navigate the health system) the concern over future healthcare costs is the biggest unknown for FIRE. I look forward to following your journey. Your blog will be a guide map for future physicians.


  6. Like the BMI and entire analogy to body types. A nice laugh for the day.
    Our expenses are very low, making our lives between lean and normal while having assets to cover between fat and mo. Fortunate, lucky and blessed.

    Adding in pensions, ss and other anuitized income adds additional safety nets. Life is good!

    How would you include anuitized payments into a BMI calculation? Multiply by 25 and add to assets?


    1. Achieving morbid obesity while being prepared to go lean is a great place to be. Any guaranteed income would shrink my numbers.

      (Annual expenses – guaranteed income) = a BMI of 1.

      An annuity that paid 25k/year would mean I now had to come up with 2,500,000 instead of 3,125,000 to achieve leanFIRE.

      I’m sure some form of social security will exist in 30 years, but I’m not banking on it with my calculations. I’ll consider it a special surprise if it shows up.


  7. You might consider adding longevity. A 30 year morbid fire wil have a significant chance of being out of money at 50 years


    1. I couldn’t agree more. LeanFIRE (25 years saved) is when I would first cut back hours at work. Morbidly obese FIRE (50 years saved) is when I would look around and accept that working no longer makes sense for financial reasons.


  8. Real FIRE SWR is 3.4% historically or more likely 3.25% going forward (source: BigERN). Let us assume investment costs make it 3.2% (100% low cost ETFs). Income taxes are still payable in retirement. Before 65 one has to pay through the nose for HI. Assuming no SS before 67. 6.25m x 3.2% = 198.4K. After 25% income tax 198.4K becomes 148.8K net. Subtracting 10K for HI leaves 138.8K/yr. Decent lifestyle? Yes. Morbidly obese vs. the current 125K of spending? Hardly.


    1. People can debate SWR from now until eternity. The overall goal of the post was to think about how different levels of FIRE would change your approach to work. Having half a century of expenses saved while still making 4 times my annual expenses working full time would be a point where I would have to examine my behavior and wonder why I was still working. I totally agree that unpredictable future tax rates and health insurance costs are some of the biggest risks with early retirement.


  9. Enjoyed the post and perspective. I just finished a 3 week vacation with the family, and it’s the first stretch since my honeymoon where I haven’t required nightly benadryl to readjust my circadian rhythms.

    FI is absolutely about eliminating aggravations through the power of saying no. Your proposed chopping block hierarchy as you approach FI is right on target: nights, weekends, holidays…amen, brother, amen.

    Liked by 2 people

    1. Ahh Benadryl – the shift worker’s faithful companion. A predictable sleep pattern would do wonders for my health and happiness. I still love emergency medicine, but I think I would love it even more Monday – Friday 9am-5pm.


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