Fitness and Logical Thinking
THINNING STRATEGICALLY: Dieting, A Game!
Instant Gratification Almost Always Results in Regret
Obesity now is as common an illness as diabetes and is markedly observed in adolescents and young adults. Especially prevalent in urban areas, this spreading medical condition stems from people’s general eating habits.
Even during the lockdown, so many of us have tried new diet plans and exercise regimes. How many could we stick with till the end? Be it a new pair of jeans which was delivered one waist size smaller or an old favorite you are trying to squeeze into, the woes of dieting have hit us all.
In order to understand our eating choices, and make better decisions, it is important to weigh the benefits of eating healthy foods against the detriments of unhealthy ones. While these are pretty obvious to most of us, the question then becomes that of seeking factors which alter expected rational behaviour.
Why do we indulge in unhealthy eating habits?
The beauty of Game Theory is that it can be applied to any real-world problem. Thus, in this article, we discuss how game theory can be applied to the art of weight loss as well.
YES, dieting too is a game — but with a twist.
Dieting as a Game
The players are the dieter’s present-day and future selves. Moreover, while a person is responsible for making their present choice, they will not be making those future choices. Instead, future versions of themselves will. The strategies available for both the players are simple, either follow a healthy diet or don’t, i.e., cooperate with your future self by sticking to your diet plan or betray them by not.
Now, if both players play optimally (don’t come up with a third strategy!), there are four outcomes possible. After your present self chooses between having an unhealthy or a healthy diet today, the future self has both these options and a possibility of a fatter or thinner self depending on the diet they follow.
Consider this too common a scenario in the pre-COVID world 😢 -
You’ve started a new diet plan, and your coworker brings a box of sweets to the work meeting. We define 4 possible outcomes as follows. For the sake of driving our point home, we will quantify the payouts.
- A thinner self in the future + jalebis now = 10 (win, win — but highly unlikely)
- A thinner self in the future + no jalebis now = 7 (win some, lose some)
- A fatter self in the future + jalebis now = 3 (pyrrhic victory)
- A fatter self in the future + no jalebis now = 0 (tough luck there)
This can be represented through a payoff table as well.
From this, it seems that the obvious answer to receive the greatest payoff is to enjoy jalebis today and refrain in the future. What a perfect excuse to indulge, right? There’s a catch. The “other player”, being the dieter’s future self faces the same options; one’s future self also has the same motive to defect and delay the dieting schedule. If the player keeps defecting, the outcome is clear. They will repeatedly skip their diet and will not see a fitter version of themselves in the foreseeable future.¹
According to the payoffs and optimal strategies one can adopt, the two equilibria are to cooperate and continue cooperating or to defect and continue defecting in subsequent games. Once the game starts, it is easier to stick to the initial strategy because doing so offers the better payoff of the remaining options.¹
We hope our little time travel activity opened your eyes!
If you have made a commitment to yourself, your best bet is to stick to it. Not only because there is some amount of guaranteed success in there, but also because you have to set a precedent for your future self. The future self is counting on you to make the harder and more responsible decisions, so it becomes a routine and the future self does not have to face the same dilemma (and maybe even defect once in a while!).
If you defect now, it is very likely that your future self will follow the same reasoning and continue the pattern (How disappointing.). Another point to consider is that more often than not, procrastination takes away the joy of the expected outcome. Delaying the better decision considerably reduces its outcomes. (“I could have lost 4 more kilos if I had started earlier”).
Sometimes we set new rules for ourselves, follow them without exception, and they take us all the way to our goal. Sometimes we follow the rules well-enough (with occasional lapses) and eventually get to our goal a little behind schedule. And sometimes our rules don’t get us all the way to our goal. Somewhere along the way, we fall off the wagon and never get back on again. It is precisely the last case that we have to avoid — lapsing so many times that our resolutions or even incentives to our future selves lose lustre and stop working.²
Dieting is a game, and we agree that the win is delivered later. But don’t you agree that a win for the future self is a win for the present self?
References:
[1] http://blogs.cornell.edu/info2040/2015/09/21/thinking-of-dieting-think-game-theory/
[3] http://blogs.cornell.edu/info2040/2012/09/12/healthy-eating-habits-and-game-theory/
With valuable inputs from Nimisha Singla.
