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Why We Gain Weight: The Damaged Feedback Loop

When people start out on a weight loss journey, they often start with the wrong questions. “What diet should I choose?” “How do I lose weight fast?” This article digs deeper, discussing the root cause of weight gain so we can better understand why we gain weight and then therefore what we need to do about it.

So what’s the root cause of weight gain?

Is it not exercising enough? Not eating the right diet? Although these things definitely influence weight gain, these aren’t the root causes.

Fundamentally, and although it’s a little more complicated than this (and I’ll get into the details later in this article), we gain weight when we eat more calories than we burn. You’ve probably heard this before, Calories In versus Calories Out (CICO), blah blah blah. The statement is true, but not always useful.

The real question that needs to be asked is WHY do we eat more calories than we burn? And after we understand why, the next question should be HOW do we stop eating more calories than we burn, and how do we start eating fewer calories than we burn, so we can start losing weight?

I struggled with weight management for decades before I finally figured it out. Diets never stuck and exercise routines led to temporary weight loss or no weight loss at all. It was only until I dug into the root cause of weight gain was I able to finally figure out the right weight management plan for myself and lose weight permanently, losing over 100 pounds in the process and keeping it off.

Before I get into the why and how (sneak peek: it’s different for everyone, but there are common reasons that I’ll describe in this article), I’ll introduce the concept of the Weight Management Feedback Loop to you.

The Weight Management Feedback Loop

The Weight Management Feedback Loop, massively simplified. I don’t talk about ghrelin, leptin, insulin, cortisol, and other hormonal factors that impact various parts of this loop. That will be a discussion for a future article.

The above image is a simplified diagram of the Weight Management Feedback Loop. I’ll start at the top. When we feel hungry, we eat. When we eat, we consume energy (calories in).

Sometimes we follow the green arrows and stop eating before we eat too much. This creates a caloric equivalence (or caloric deficiency), and we maintain our weight (or lose weight). Sometimes we follow the red arrows, which creates a caloric surplus. This excess energy gets converted to fat, and then we gain weight.

Naturally thin people for almost all their meals follow the green arrow for one reason or another, independent of the other variables.

The rest of us often follow the red arrows from time to time, slowly gaining weight. Sometimes we regularly follow the red arrows for most of our meals, rapidly gaining weight.

If we can take the green path more often than the red path, we can succeed with weight loss. So why do we take the red path?

Why We Take The Red Arrow Path and Gain Weight

This question is absolutely underrated in the weight loss industry. People always immediately jump into solutions first, but it’s important to ask this question first. The truth is, the answer is different for everyone, and there are multiple reasons. No, it’s not as simple as “not enough willpower” (although willpower contributes to success). We choose the red arrow path because of our environment, our diet/nutrition, and our mentality.

Side note: our hormones actually play a significant factor in why we take the red arrow path, but our hormones are impacted significantly by the three factors above. Hormones, although important, will be the topic for a future article.

Our Environment

I remember starting a new job where there was literally free food in the office kitchen multiple times a week and multiple times during the day. I love a good deal, and free is hard to resist, so I ate a ton of the free food. I gained 20 pounds the year that I worked there.

Millions of us have gained weight due to COVID-19 changing our environment such that we are less active, and work from home has made many of us spend more time closer to our kitchens, snacking more. The reason for this weight gain is due to environmental change.

Obesity levels differ significantly between different countries. Sure, some of this may be genetics, but it is largely due to environment. In Vietnam where much of my family is from, for example, the obesity rate is the lowest in the world. I live in Canada, which has one of the highest obesity rates in the world. Guess what? I was obese for the majority of my adult life.

My ancestry is Vietnamese. I lived in Canada. My parents who lived in Vietnam most their life were thin. I lived in Canada and was obese.

Your environment matters more than your willpower. Change your environment, and you’ll change how often you follow the green path versus the red one.

Our Diet/Nutrition

I mentioned above that the root cause of weight gain isn’t diet – it however is a major source of why we may or may not overeat. Most diets DO work, if you stick with them. Furthermore, even if you go on a fantastic diet to lose a ton of weight, if you go back to your original diet where you were overweight, you will likely gain the weight back. This is why it’s important to pick a diet that is sustainable and one that you see yourself committing to for the rest of your life. A successful diet is a lifestyle change.

Diets affect our satiety levels. If we feel full faster, we eat less. If we eat empty calories such as addicting snacks and sugary drinks, we will feel less full, and overeat.

This is why keto and vegetarian diets can be very successful: the diets naturally lend themselves to making us feel full before we overeat, due to their focus on satiating fats (for keto) and fiber (for vegetarian diets). This is also why the standard American diet often leads to us overeating: it is filled with sugars, refined carbohydrates, non-satiating fats, and other types of foods that keep us hungry even after we’ve eaten a sufficient number of calories. However, if you overeat on a keto or vegetarian diet, you will still gain weight. Crazily enough, if you undereat on a terrible diet, you can still lose weight too.

Intermittent fasting works for some people because it reduces the number of opportunities for us to take the red arrow path, and also increases the time that we are in the “burn calories” part of the Weight Management Feedback Loop. However, if you overeat on the meals that you do eat, you will still gain weight with intermittent fasting.

Remember though: this is just one factor in the three that matter for whether or not we overeat. I for example did not go on a restrictive diet at all, and still lost 100 pounds. Any diet can work for weight loss if you use it to eat less than you burn. Similarly, any diet can fail if you use it to eat more than you burn.

Our Mentality

Has your weight ever changed because of stress? Do you stress eat, or binge? I know that for me, I lose weight in times of anxiety, and gain weight in times of stress. For example, when my father passed away, I lost 5 pounds in 2 weeks and barely wanted to eat. After we had the funeral, my anxiety was reduced, but having to deal with the estate as the executor and having to catch up on lost work caused me to regain that weight plus more the following month.

My father passed away December 2018, and the anxiety I felt dealing with the loss created rapid weight loss. The stress of having to deal with the loss after the anxiety was reduced cause rapid weight gain.

If there are issues with our mental health, we will have challenges with successfully implementing a weight management plan. Unfortunately for some this can lead to a vicious cycle where our weight affects our mental health, which weakens our ability to lose weight, which then affects our mental health even more. On the flip side however, if we can gain small successes with our weight loss plan, our confidence can start to improve, improving our mental health which creates a virtuous cycle where we can succeed even further with our weight loss.

I am also absolutely convinced that you’ll fail if you don’t believe that you can lose weight. This is one of the reasons why I never even tried to lose weight for the majority of my life. Once I finally found a way to believe in myself, I started succeeding.

How Do We Start Eating Fewer Calories Than We Burn?

Now that we know why we eat more calories than we burn, how do we tip the scales the other way around such that we can start eating fewer calories than we burn? To do this, we permanently change our environment, and/or our diet/nutrition, and/or our mentality.

Furthermore, for some of us, it may actually not take much. Even a small permanent change can add up to thousands of calories not eaten, and therefore tens or even hundreds of pounds lost.

The key word is permanent. Any temporary change in these three factors can create temporary weight loss, but if things go back to the way they were before, odds are that the weight will come back.

This is also the reason why there are so many ways to succeed with weight loss, and so many ways to fail. If you start off on a keto diet but your environment surrounds you with free sweet sugary treats and your mentality can’t resist free stuff, it’s going to be hard to stick with that keto diet.

My recommendation on how to start is to read my article about micro-lifestyle changes, pick some that you believe would work for you, and then experiment with changes that you can stick with permanently. Keep track of your weight and see what works and what doesn’t. Stick with the things that work and abandon the ones that don’t.

For me personally, a shift in mentality was the major reason I was able to lose weight and keep it off. When I first started my successful weight loss journey, I was a brand new dad with a lot more responsibility than I had in the past. My environment was probably worse for weight loss because I had a lot less time than before. I wasn’t much of a cook and I wasn’t about to tell my wife that she should be changing the way she cooks just for me, while dealing with her own added responsibilities of being a new mom, so changing my diet would have been challenging. What I did have, however, was a newfound desire to lose weight since it was critical that I improve my health to be around for my son. This defining motivation was a big source of how I was able to succeed.

Use Luuze to Rewire Your Weight Management Feedback Loop

I started understanding myself and my body better through weighing myself daily. I started recognizing when I overate and when I did not, slowly rewiring my brain to repair my Weight Management Feedback Loop. Through regular reflection, I started recognizing the times I was taking the red arrow path and gaining weight and the times where I was taking the green arrow path and losing weight. I realized that the scale lies, so as an engineer, I did some math to make my weight measurements more aligned to what was happening in reality. I reflected on the times where I screwed up, the times where I got demotivated, and the times where I was motivated. I slowly repaired my Weight Management Feedback Loop as I absorbed all this knowledge through my direct experience of losing 100 pounds. I then put all this knowledge into Luuze.

Luuze focuses on helping people lose weight permanently by rewiring their Weight Management Feedback Loop. Weigh yourself regularly, then reflect on the past day, using the questions that the virtual coach asks you. If you keep on doing this, you will:

  • Get an accurate sense of your progress through trend weight measurements, not lies from the scale
  • Now that you have an accurate sense of your progress, start to recognize when you took the red path and overate, or when you took the green path and successfully lost weight
  • Be warned if you are getting off track, and be given guidance on how to get back on track
  • Get your motivation boosted when you’re on a weight loss streak

I felt that too many apps focused on fitness or diet, when fixing this feedback loop was truly the source of permanent weight loss. If you’ve tried other apps and failed to lose weight permanently, try Luuze instead. Furthermore, Luuze can be used in tandem with a diet or exercise plan or even other apps to accelerate weight loss and lock in the losses.

What About Exercise and Metabolism?

You’ll notice that I haven’t talked much about exercise and metabolism, two very important factors that influence weight management. The truth is that even if you don’t exercise, you can still influence the three factors of environment, diet, and mentality to lose weight. Also, if your metabolism is poor, you are definitely going to have a harder time losing weight than someone who has an incredibly high metabolism, but again, the three factors can be changed to lose weight.

Exercise is amazing and if you can fit it in, do it. There are massive health benefits in doing so beyond just weight loss. More exercise does not guarantee weight loss however, because it is very easy to just start eating more as your body burns more calories.

And although there are some of us that have such terrible metabolism that it is an extreme challenge to lose weight, if you want to succeed, it’s important to not use that as an excuse to not believe and to instead find a way to be at peace with going slower.


Don’t just jump into weight loss, jumping into an unsustainable diet or unsustainable exercise routine. Instead, reflect on what you need to do to change your Weight Management Feedback Loop permanently, and start making the changes necessary in your life to do so. If you do this, the odds are significantly greater that you’ll lose weight and keep it off.