When it comes to health, I often hear people say, “Warren Buffett drinks Coke and lives a long life.” Others dismiss the topic entirely: “Why bother? Health is something you’re born with.” But that’s not hard to refute. Studies have shown that “eating well and living well” is about 70 percent lifestyle and 30 percent genetic. Jean-Marc Lemaître, a French expert on the mechanisms of aging, estimates lifestyle accounts for as much as 90 percent, based on recent research. What the questioner is really saying, though, is something closer to: “I don’t want to be nagged into doing something I don’t want to do anyway.” They simply don’t like being told to make small changes now for the sake of the future.

Here’s where you might feel tempted to get emotional and push back. Yes, a few rare individuals have survived parachute failures while skydiving. But that doesn’t mean we should eliminate parachutes from standard skydiving procedures. In the same way, medicine -- grounded in scientific evidence -- offers proven strategies for slowing aging and preventing disease. It’s irrational to focus on outliers and use them as counterexamples to ignore what overwhelmingly works for most people.

Your head may understand -- but your heart often doesn’t. Let’s find why people binge drink for the fleeting pleasure of the moment, even though they know they’ll regret it tomorrow, and why we indulge in short-term gratification while anticipating a long list of potential diseases decades down the line.

The answer lies in a concept called “future self-continuity” -- the degree to which people feel connected to their future selves. Many tend to perceive their future “me” as someone separate from who they are today, which makes it harder to factor long-term interests into present decisions. As philosopher Derek Parfit noted, if your future self feels like a stranger, your present self has little motivation to act on their behalf.

Neuroscience backs this up. Brain imaging studies have shown that the regions activated when we think about our present selves are significantly less active when we consider our future selves -- showing a response pattern similar to how we think about other people. Moreover, the greater this gap in brain activity, the more likely individuals are to favor immediate rewards over future benefits.

Why, then, did the human brain evolve to place such limited value on the future self? Evolutionary psychologists trace the answer to changes in our environment over time. For most of the 200,000 years of human evolution, the future was deeply uncertain, and long-term rewards were rare.

For example, advising a caveman to store the food in front of him for abundance a year from now would have been absurd. With no way of knowing whether a predator might attack tomorrow or a drought would strike next month, natural selection shaped us to prioritize the tangible benefits of the here and now.

Our decision-making is a constant tug-of-war between immediate gratification and long-term rewards. This becomes clear when you're eyeing a tempting dessert while thinking about your health, or when you’re torn between spending your paycheck right away and saving for retirement.

In behavioral economics, this tendency to devalue future rewards over time is known as “temporal discounting.” It often appears as present bias, or the tendency to overemphasize immediate pleasure. For example, when given the choice between receiving $1,000 now or $1,100 in a month, many people choose the immediate $1,000. However, when the same choice is set in the future -- $1,000 in a year versus $1,100 in a year and a month -- people are more willing to wait.

This shows that discounting isn’t linear but hyperbolic: the perceived value of a reward drops sharply the closer it is to the present. As a result, we tend to overvalue immediate rewards and undervalue those in the distant future. This trade-off between instant pleasure and delayed benefit has profound implications for both health behavior and financial decision-making.

Dr. Abraham M. Rutchick and his colleagues at California State University, Northridge (CSUN) conducted a direct experimental test of the relationship between perceived similarity to one’s future self and health-related behaviors. By measuring participants’ self-reported present-future self-continuity, they found that those with a stronger sense of connection to their future selves reported better health across various measures and tended to maintain healthier habits. Conversely, individuals who were less future-oriented and more impulsive were more likely to engage in unhealthy behaviors such as obesity, smoking, and substance abuse. Notably, those who severely devalued their future selves were also more likely to die within five years.

Given this human instinct, researchers are exploring ways to help people connect more deeply with their future selves. In one Stanford University experiment, college students were shown virtual reality (VR) images of themselves in their 70s. After the experience, they were more likely to contribute additional money to their retirement accounts. Seeing your future self as a continuation of who you are today -- not as a different person -- can inspire meaningful behavior change.

In another study, students wrote letters to their future selves 20 years ahead, artificially strengthening their sense of connection. Those students exercised more over the following two weeks. Similar findings have emerged around eating habits: when participants were reminded of long-term health consequences just before choosing food, they tended to pick options with fewer calories and better nutrition -- and they decided faster, with less hesitation. Conversely, when prompted to focus only on short-term factors like immediate flavor, people were more likely to choose unhealthy foods.

While we are instinctively prone to losing the tug-of-war between our selfish present self and our vulnerable future self, studies show that simply practicing acceptance of our future self as “me” can lead to meaningful behavior change and a better life. When you step back and consider it, your future self is simply a continuation of who you are today. The more you honor and care for that awkward, unfamiliar future self, the richer the life you will ultimately receive in return.

Jung Hee-won is a geriatric physician. He graduated from Seoul National University College of Medicine and trained at Seoul National University Hospital. During his med-school days, while practicing the horn, he realized the importance of muscle maintenance and became interested in sarcopenia. His main research interests include frailty, sarcopenia and establishing age-friendly health systems for acute hospitals. This column was originally published in Chosun Ilbo in Korean on July 1, 2025. -- Ed.