The Sunk Cost Fallacy in Health: Let go of failures, start anew wisely.

Introduction: When past sunk costs become a burden in the present.

As a rehabilitation physician who has cared for patients for over a decade, I've observed a recurring pattern in my clinic: patients coming to me with chronic pain, overweight, or other health problems often say, "Doctor, I've tried everything, nothing works. I probably can't do it," or "I've wasted years and money on weight loss programs; now I don't want to try anything anymore."

Readers who are in the financial field are likely familiar with the term "Sunk Cost Fallacy," which refers to consistently making the same decisions because a significant amount of time, money, or effort has already been invested, even though one knows it's not worthwhile or won't yield results. Today, I'd like to invite you to examine how this phenomenon affects our health and how we can escape this trap.

understand Sunk Cost Fallacy

In the financial world, sunk costs refer to expenses already incurred and cannot be recovered, such as research and development costs for a failed product. A sound economic decision-making principle is that we should not consider sunk costs in future decisions because they are in the past. What matters is the expected future return, not the loss in the past.

But human nature isn't like that. We often regret what we've invested and try to make it worthwhile by continuing to invest, even knowing it's unlikely to yield good results. A classic example is watching a boring movie to the end because "I already paid for the ticket," or finishing a plate of food even after being full because "I paid for it."

Sunk Cost Fallacy In the field of health: Common patterns.

1. The trap of past failures.

"I've lost weight five times already, but each time I gained it back even fatter. I've spent tens of thousands of baht. I'm not trying again this time." This is the sentence doctors hear most often.

Mr. A, a 45-year-old branch manager of a bank, has spent over 200,000 baht on various weight-loss programs, from premium gym memberships and meal replacement programs to weight-loss pills and expensive exercise equipment that has now become just clothes hangers at home. Each time he started, he was very determined, but after 2-3 months, he would revert to his old habits, and the weight would return with compound interest.

When Mr. Somchai first came to see the doctor, he said, "Doctor, I don't think I can do it anymore. I've been trying for 10 years, wasting a lot of time and money. Now I give up." This is a textbook example of the Sunk Cost Fallacy. He placed too much emphasis on past failures, which became an obstacle to starting anew, when in reality, every new beginning is a new opportunity unrelated to past failures.

2. Sticking to old methods that don't work.

“I’ve been running for six months, but my knees still hurt. But I’ll keep running because I’ve already wasted enough time,” said Wipa, a 38-year-old investment analyst, who came to see a doctor with chronic knee pain. She explained that she started running for health six months ago, but her knees began hurting in the second month. Instead of stopping or changing her approach, she told herself, “I have to fight. I have to run for a full year as I’ve planned,” because she felt that if she stopped now, the past six months would be wasted.

This is an example of clinging to a plan even when the body is sending warning signals. As a doctor, I must say that insisting on exercising in a way that increases pain is not willpower, but dangerous stubbornness. After a physical examination, it was found that Ms. Wipa had a minor knee problem that made long-distance running unsuitable. The doctor recommended cycling or swimming instead. She hesitated greatly, thinking, "What about the six pairs of running shoes I already bought?" But when the doctor explained that the cost of future knee surgery was far greater than the cost of six pairs of shoes, she finally let go.

3. Continued investment in inappropriate things.

"I paid for a year of gym membership in advance, but I've only been three times. Now I don't want to go because I'm embarrassed in front of people there, but I still haven't canceled the subscription."

Mr. Prasert, a 42-year-old credit manager, purchased a one-year prepaid fitness membership for 18,000 baht, intending to exercise after work. However, he only went three times in the first month and then stopped. Every time he thinks about it, he feels guilty and stressed, but he hasn't really gone. The 18,000 baht has become more of a psychological burden than a motivation.

The doctor told him that the 18,000 baht was a sunk cost. Whether you go or not, you can't get that money back. The important thing is to find an exercise method that truly suits your lifestyle, not force yourself to go to a gym you dislike just because you've already paid. Perhaps a 30-minute brisk walk in a nearby park after work might be more effective, and more importantly, sustainable.

why Sunk Cost Fallacy Therefore, it is dangerous to health.

1. It wastes valuable time and opportunities. Time is the most valuable and irreplaceable resource. Sticking with ineffective methods simply because you've already invested in them means incurring "opportunity cost"—the cost of missing the opportunity to try a new, potentially more effective method.

Mr. Somchai, whom the doctor mentioned earlier, spent 10 years trying to lose weight using the same ineffective methods. If he had admitted from the beginning that those methods weren't suitable for him and changed his approach, he might have been healthier 5 years ago. Moreover, during those 10 years, excess weight and complications such as diabetes, high blood pressure, and high cholesterol began to accumulate, causing long-term damage to his body.

2. It causes stress and is toxic to the mind. Feeling guilty about past failures or wasted money creates immense stress. This chronic stress affects cortisol levels in the body, which is one of the causes of various chronic illnesses, including heart disease, diabetes, and depression.

Research has shown that individuals who repeatedly experience failure in weight loss (weight cycling) are more likely to have depression and lower self-esteem than those who have never attempted to lose weight, even if their weight difference is not significant. This demonstrates that the psychological burden of failure may be more serious than the problem of being overweight itself.

3. It hinders learning and adaptation. A key principle in rehabilitation medicine is the "Individualized Approach," which means tailoring treatment plans to each individual. There is no one-size-fits-all approach. Sticking to the same method simply because you've already invested in it prevents you from learning what truly works for you.

Wipa, who insisted on running despite knee pain, would have discovered that swimming was more enjoyable and relaxing, and most importantly, less damaging to her knees, if she had been open to trying other methods. This learning experience would have been worth more than the six pairs of running shoes she bought.

Principles of making smart health decisions: Lessons from the financial world.

1. Look to the future instead of the past.(Forward-Looking Approach) When making investment decisions, a good financier looks at expected future returns, not money lost in the past. This principle applies to health as well.

Questions you should ask yourself:

• Will this method help improve my health in the future?
• What are my realistic and sustainable chances of achieving this?
• Are there other methods that might work better?

Questions you shouldn't ask:

• How much money have I lost?
• How much effort have I put in?
• What will people think if I change my mind?

When Mr. Somchai started thinking this way, he realized that trying a new approach didn't mean the past 10 years were invaluable, but rather that the experience revealed what didn't work for him—valuable information. This time, he chose a program with weekly monitoring and evaluation, a dietitian and physical therapist to help adjust the plan, and importantly, a focus on long-term behavioral change rather than short-term results. After one year, he lost 15 kilograms and has maintained that weight to this day.

2. Use the Portfolio Approach: Try several methods simultaneously. Smart investors don't put all their eggs in one basket; they diversify their risks by investing in various assets. We can apply this principle to health as well.

Instead of telling yourself, “I have to run every day,” which will make you feel like a failure if you don’t, try thinking like this instead: “I will have many options for physical activity. On days when I have time and the weather is nice, I'll run. On rainy days, I'll exercise at home. On days when I'm very tired, I'll just go for a walk after dinner.”

Having multiple options prevents us from becoming too dependent on one method. If one method doesn't work, we can switch to another without feeling like we've wasted time.

3. Set a Stop-Loss: Know when to stop. In trading, investors often set a stop-loss point, which is the level at which they are willing to accept a loss and exit the investment, to prevent further losses. This principle is crucial in managing your investment health.

Example of configuration. Stop-Loss in Health:

• If you experience increased pain from any exercise within two weeks, stop and consult a doctor.
• If a weight loss method isn't showing results within 3 months, or is causing you significant stress, consider changing methods.
• If taking medication or supplements causes side effects that interfere with your daily life, stop and find alternatives.

Having a clear stop-loss order helps us know when to let go, without waiting until we've lost too much.

4. Evaluate ROI regularly. Return on Investment (ROI) is a key indicator for financial decision-making. We should regularly evaluate the ROI of healthcare investments as well.

Assessment methods ROI in the health sector:

• Set measurable goals, such as reducing your waist circumference by 5 cm in 3 months.
• Record your results regularly, such as weighing yourself weekly and measuring your blood pressure monthly.
• The assessment shouldn't be based solely on numbers, but also on feelings, such as whether you slept better or had more energy.
• Review every 1-3 months to determine whether to continue, adjust the plan, or change the approach.

Mr. Prasert purchased a fitness membership for 18,000 baht but only attended three times. If he evaluated the return on investment (ROI), he would find that the cost per session was 6,000 baht, which was clearly too expensive. Deciding to cancel and find a more economical and practical alternative was therefore a wise decision.

Fresh Start Effect: The Power of New Beginnings

Psychological research has discovered an interesting phenomenon called the "Fresh Start Effect," which means that people are more motivated to change their behavior during times that resemble new beginnings, such as the beginning of a new year, a birthday, a Monday, or the beginning of the month.

This is good news for those who have failed in the past regarding their health, because it means that every day is a new opportunity to start over. You don't have to wait until next year, next month, or next Monday; you can start now.

How to take advantage of Fresh Start Effect

1. Create a clear starting point. Don't just say, "I'll start someday," but set a clear date, such as "next Monday" or "the first day of next month." Having a clear starting point helps us feel like we're opening a new chapter in life.
2. Change the environment. Changing your environment signals to your brain that this is a true new beginning. This could be changing your commute to work to walk more, rearranging your workspace, or buying new workout clothes.
3. Announce it to those close to you. Telling others you're starting over helps you maintain accountability and gain support. It also "cuts the bridge" to prevent yourself from easily backing down.
4. Set new goals that are different from the old ones. If your original goal was "lose 10 kg in 2 months," which failed, try setting a new goal: "walk for 30 minutes at least 5 days a week for 3 months." Shifting from outcome-based goals to behavioral goals is often more effective.

Case Study: Letting Go and Achieving Success

I'd like to share the story of Mr. Anan, a 50-year-old director of risk management at a bank. He came to see me with chronic back pain that was interfering with his work and daily life.

Mr. Anan said he had been getting massages from the same masseuse for three years, twice a week at a cost of 1,000 baht each time, totaling approximately 300,000 baht. However, his back pain hadn't improved, and sometimes even worsened after the massage. Despite this, he continued because he thought, "I've already spent a lot of money, I have to keep going until it's gone." Furthermore, he felt a connection with the masseuse and didn't want to disappoint her.

After a physical examination and review of X-rays, it was found that Mr. Anan had a slight spondylolisthesis, or spinal misalignment, and very weak deep back muscles. Therefore, the strong massage he received not only didn't help but might worsen his condition.

The doctor explained to him that the 300,000 baht he had already spent was a sunk cost, and no matter what he did, he couldn't get it back. The important thing was what he could do to truly improve his back from now on. The doctor recommended a physical therapy program focusing on strengthening core muscles and correct posture.

Anan hesitated for a long time, feeling guilty about "abandoning" his usual masseur. But after much thought, he decided to give it a try. The result was that after three months of consistent physical therapy and adjustments to his work posture, his back pain improved so much that he could return to his normal life. He said, "If I had decided to change my approach from the beginning, I wouldn't have suffered in pain for three years."

Practical Strategy: How to Win Sunk Cost Fallacy

1. Practice mindful "cutting losses". Just as skilled traders know how to cut losses without hesitation, we too must learn to let go of what doesn't work.

exercise :

• Write a list of everything you are doing for your health.
• Ask yourself honestly, "If I could start over today, would I choose to do this?"
• Anything that the answer is "no" to, that's something you should consider stopping or changing.

2. Separate the “effort” from the “result”. Your past efforts have value in themselves, even if they didn't yield the desired results. It shows you care about your health, which is good. However, clinging to the same methods because you've tried so hard before isn't honest with yourself; it's stubbornness.

Think of every try and failure as data collection. You learn what doesn't work for you, bringing you closer to discovering what does. Scientists don't call failed experiments "failures," but rather "data."

3. Use “new money” to make decisions. There's a financial technique called the "Mental Accounting Trick." Imagine you receive 100,000 baht to invest in your health. How would you use it? Your answer is about what you should really be doing, not what you're doing because you've already invested it.

Helpful questions:

• If I have 5 hours of free time per week, how can I use it for my health?
• If I have 10,000 baht a month for health expenses, how should I use it?
• If I were to give advice to a friend who is in a similar situation, what would I recommend?

4. Create an accountability system. Having someone to follow and support us helps us avoid falling into the Sunk Cost Fallacy.

วิธีสร้าง Accountability:

• Find a workout buddy who can remind and encourage you.
• Hire a coach or trainer to evaluate your progress and adjust your plan.
• Join a support group, such as a weight loss group or a running group.
• There is a doctor or dietitian monitoring your progress.

The important thing is that these people must be the ones who are brave enough to tell you the truth, not just offer encouragement. They must be brave enough to say, "This isn't working. Let's try a different approach."

5. Celebrate letting go. Deciding to stop doing something that isn't working is an act of courage, not a failure. Celebrate every time you dare to let go and start anew.

When Somchai decided to stop following the same old weight-loss programs and start a new one focused on behavioral change, he considered it the beginning of a new chapter. He held a small party with his family to announce his commitment to this new path. Doing so made him feel proud and more motivated.

Summary: The wisdom of letting go.

In the financial world, successful investors are those who know how to cut their losses and move on to new opportunities. They don't dwell on past mistakes but learn from them and improve.

Like health, success isn't measured by never failing, but by the ability to get back up after failure and the courage to change when you know the old way isn't working.

Remember this:

• Time, money, and effort have already been spent. Sunk Cost It should not determine future decisions.
• Every day is a new opportunity. To begin, there's no need to wait until next year.
• Failure is data. That helps you know what doesn't work for you.
• Letting go is an act of courage. It is not weakness.

Your health is the most important investment in life. Don't let the Sunk Cost Fallacy prevent you from getting the best return. It's always possible to start over, and that can begin today. And remember that. "In investing and in life, what's important isn't never making mistakes, but rather not dwelling on those mistakes."

Finally, I hope this article will encourage everyone who feels discouraged about their health to reconsider and start taking care of their health again. See you again next month!

Dr. Monthonlee Sutthitham
Rehabilitation Medicine Specialist
Thonburi Hospital

educational record

• Doctor of Medicine, Srinakharinwirot University, 2555
• Certificate of Rehabilitation Medicine, Khon Kaen University, 2558