Help us create a fair weight loss bet...

March 12, 2008 8:20 AM

Help us create a fair weight loss bet...

So, my brother has proposed a £20 bet on who can lose the most weight between now and November (when he returns from a secondment to Australia). On talking about this, we obviously need to work out the rules of this, so I'm turning to you guys to help make this a safe and fair wager...

The facts...
Him : 28 years old; 6ft tall; 15.25stone/213lb/96.5kg with a mental target of 13st/182lb/82kg; willing sportsman with a love of beer and crap food.

Me : 31 years old; 6ft5 tall; 23.5st/330lb/150kg with a mental target of 17st/238lb/108kg; sloth-like sugar eating creature who's only exercise is a sunday walk and using a recumbent bike.

We're currently thinking that percentage of (current-target) is a good idea, but we have no idea if this is fair or if our targets are sensible. Thoughts...?

posted by twine42 to health & fitness (14 comments total)

You're looking at a period of 34 weeks, give or take a few. It's generally recommended that people trying to lose weight should not lose more than two pounds a week, so the maximum safe weight loss for that period would be about 68 pounds, which is less than your target.

I'd measure it as a percentage of current minus target, or maximum safe loss, whichever is less). Thus his weight loss would be measured as a percentage of 31 pounds (current-target), while yours would be measured as a percentage of 68 pounds (or whatever twice the exact number of weeks you're covering is), so you're not trying to actually lose 92 pounds in eight months.

Or use 1kg/week or 0.15 stone/week, if you prefer those units.
posted by DevilsAdvocate at 8:30 AM on March 12, 2008

In declining order of cost and meaningfulness:

Go in for hydrostatic body fat testing before and after, compare loss in body fat percentage (as a ratio from start to finish, e.g., going from 26% to 22% beats going from 30% to 26%)

Get a Tanita body fat testing scale, otherwise as above.

Compare ratio of BMI before and after.
posted by Zed_Lopez at 8:32 AM on March 12, 2008

That's a lot of fucking weight to lose for you, and no slouch for him, either. You're going to have to commit pretty heavily to major changes in your day-to-day life. It would likely be better if you did monthly weigh-ins, to break the goal up.

My assessment: he's closer to a normal BMI, but his goal is less than 25 which gets him into that normal range. As you get lighter, it's harder to lose weight. On the other hand, your goal is midrange in the "overweight" range, where one can still lose weight pretty readily. So it's pretty even on that front. Since he's already more sport-inclined, knowing nothing more about you two, I'd say he has a significant advantage.

Make it for 100 quid, maybe more - that'll push you!
posted by notsnot at 8:33 AM on March 12, 2008

Doesn't sound fair to me, since his target requires losing about 15% of his weight, and yours requires losing about 28% of yours. Losing a stone/pound/kg requires the same amount of reduced calorie intake, or the same amount of calories burned during exercise, no matter what weight you start from. (With some debatable variation due to differences in metabolism.)

So, you ought to set equal percentage loss gains. His 15% is probably reasonable for his height. So set yours at 15% as well (20.2st/280lb/127.5kg). Whoever hits the target first, or has the biggest loss by November, wins. You'll want to keep going after that, probably, because your stated mental target would be a much healthier weight for you.
posted by beagle at 8:37 AM on March 12, 2008

I believe "The Biggest Loser" does percentage of weight loss from starting weight:
(213-182)/213 = 15% weight loss
(330-238)/339 = 28% weight loss
You would win if you reached your target, but you would also win if your target was a "modest" 277 lbs. They don't bother with "targets", just maximizing total % of weight loss.

The way you are proposing the bet is % of reaching target. So if he reached his goal of 182, and you both lost 15% of your starting weight, you'd be only be 58% towards your target.

So, I'd do % of starting weight.
posted by yeti at 8:38 AM on March 12, 2008

Instead of competing directly against each other in terms of total pounds lost, why don't you each pick a reasonable goal and then bet on whether you can individually reach it? Set and agree on healthy goals for each of you and when November comes around if one has reached their goal and the other hasn't then the loser pays the winner. If you BOTH reach your goals, then pool the bet funds and do something fun together. It's still a competition but it's going to be fairer to both of you in the end. Your weights are so different and your goals so far apart that competing with one another in terms of pounds lost or total percentages just doesn't make much sense.

(I'd also consider revising your goal weight. You're looking to lose 100 pounds in just over eight months. If you're looking to keep the weight off you're going to want to lose a little slower than that. Don't forget to account for all that muscle you'll probably put on when you start exercising.)
posted by LeeJay at 8:52 AM on March 12, 2008

Sorry... as always I failed to explain something correctly. :)

The targets are the weights we'd like to reach to feel healthier rather than necessarily a target for november. It would be nice, but I know it's unobtainable. It was born of the concept that we should do it as a percentage success between current and a BMI 'ideal' that turned into an argument about why BMI figures are crap. :)
posted by twine42 at 9:03 AM on March 12, 2008

Let me respectfully suggest that making a bet regarding total weight lost eight months away may be counterproductive. I am basing this on these assumptions:

(1) You (and your brother) want to become fitter and healthier, part of which involves losing weight.

(2) Your ultimate goal is not just to lose x number of pounds by November, but to keep it off for good.

(3) Achieving (1) and (2) requires real - and, in your case, radical - lifestyle changes, including eating more nutritiously and getting regular exercise.

(4) You have not made these lifestyle changes in the past in part because you have lacked the discipline to do so, perhaps because when you have tried to exercise or diet, you have not seen immediate results.

Setting a single goal many months provides incentive only to reach a specific target weight on a specific day, not change your behaviors in order to become fitter and healthier long term. You can do a crash exercise-and-diet regimen that may take off a bunch of pounds come November, but as others have pointed out, losing weight quickly is not necessarily a means of becoming fitter and healthier. Moreover, after the target date has come and gone, then what? Will you continue your regimen, or will you say "thank god that's over!" and return to your old habits?

For these reasons, I suggest (as others already have) that you and brother agree on a number of interim goals that encourage behavioral changes, rather than a single target weight loss. For example, you may set a goal of exercising for X hours each month for eight months - winner each month accumulates "points" towards the ultimate amount. Or you might set exercise-specific goals such as running x number of miles in y amount of time. Interim weight goals can also be targets.

And, if my assumptions are wrong, please feel free to disregard entirely!
posted by googly at 9:17 AM on March 12, 2008

If you can both agree on what are reasonable goals for November, then make your bet based on percentage of reasonable goal achieved. So, his reasonable goal for November might be all of it (or all but the last 5lbs or whatever), while yours is some smaller than all of it number. Then the winner is whoever loses the larger percentage of the weight in question.

As an alternate to weight or BMI based numbers, you might also consider making your bet based on clothing sizes reduced since that tends to reflect the actual slimming changes in your body more accurately.
posted by jacquilynne at 9:19 AM on March 12, 2008

Since BMI (Body Mass Index, not the airline) is a more relevant measure of health, how about measuring who changes their BMI the most?
posted by OlderThanTOS at 9:34 AM on March 12, 2008

an argument about why BMI figures are crap

I agree wholly that BMI is an incredibly flawed metric (hence its being last on my list.) But for all its flaws, I'd still rate a comparison based on it to be more meaningful than one based on two independently and arbitrarily chosen targets, which ends up comparing your abilities to estimate your targets and your ambitions as well as any accomplishments.
posted by Zed_Lopez at 9:53 AM on March 12, 2008

comparing your abilities to estimate your targets

I agree. Reminds me of the card game "Oh Hell", of which whose winner is the person who can most accurately predict how many tricks they will win and not necessarily getting the most tricks.
posted by yeti at 10:12 AM on March 12, 2008

After determining how you will measure 'success' in terms of your bet, make sure its clear that if you both hit your goals, then the bet is off. You should not be competing against each other as much as you are competing against your target weight.

Good luck!
posted by wabashbdw at 10:17 AM on March 12, 2008

I agree with Zed_Lopez above. Measure body fat percentage rather than weight. A third option for measurement is using calipers.
posted by Thoughtcrime at 2:03 PM on March 12, 2008