Why Obesity Is a Medical Condition | Dr. Jessica Sanchez
Beyond Diet and Exercise: Why Obesity Should Be Treated as a Medical Condition
By Jessica Sanchez-Alfaro, MD
Published: April 2025
Reading time: ~10 minutes
Obesity isn't a personal failure. It's a chronic medical condition that deserves treatment, not judgment.
For most of my life, I believed that if I just tried hard enough, I could control my weight. As a physician, I knew all the "right" things to do. And yet, despite my best efforts, I carried 80 extra pounds on my small 5-foot frame. I wasn't lazy. I wasn't unaware. I was simply up against biology.
You may be, too.
What You Need to Know
Obesity is driven by biology, not lack of willpower
Your body has built-in defenses against weight loss
Genetics plays a significant role
Modern life makes healthy habits hard to sustain
Medical treatment can help
Your Body Has a "Weight Thermostat"
Your brain regulates body fat like a thermostat maintains room temperature. When you try to lose weight, your body fights back. It responds by:
Increasing hunger
Decreasing fullness
Slowing your metabolism
Encouraging fat storage
This isn't a glitch. It's how your body protects you from perceived starvation. But in the modern world, it often works against you.
Why You Can't Just "Eat Less and Move More"
You've probably heard that weight loss is simple math: eat fewer calories than you burn. But real life doesn't work like that. Why?
Because after you lose weight:
Your body burns fewer calories at rest
Your hunger hormones increase
Your fullness hormones decrease
These changes can last for years—long after the diet ends.
Example: The Biggest Loser Study
Researchers followed contestants from the show The Biggest Loser for 6 years:
Most regained the weight
Their metabolisms stayed suppressed by 500-600 calories per day
Hunger hormones stayed high
This shows how strong your body's defense of its highest weight can be.
Hunger Is a Hormonal Signal
If you feel like you're constantly battling hunger, you're not imagining it. Two key hormones play a big role:
Leptin: Your Satiety Signal
Made by your fat cells
Tells your brain: "We're full."
In obesity, your brain becomes resistant to it
Ghrelin: Your Hunger Hormone
Made by your stomach
Tells your brain: "Time to eat"
Levels rise after weight loss, making you feel hungrier
It's not willpower. It's your hormones doing their job.
Genetics Load the Gun
Why do some people stay thin without effort while others gain weight easily? A large part of the answer is genetics:
70-90% of body size is genetically determined
Identical twins, even raised apart, have similar body weights
Children resemble the weight of biological parents, not adoptive ones
You didn't choose your genetics. But you can choose how to respond.
Modern Life Pulls the Trigger
Our ancestors evolved in food-scarce environments. Today, we live in a food swamp:
Constant exposure to high-calorie foods
Processed combinations of sugar, fat, and salt designed to hijack hunger
Sleep deprivation, stress, and sedentary routines
Modern life is set up to make weight gain easy—and weight loss hard.
Obesity Is Not a Character Flaw
Let's be clear:
Obesity is a chronic disease
It increases the risk of type 2 diabetes, heart disease, sleep apnea, infertility, and some cancers
It's not cured by short-term diets
It deserves long-term medical care
I used to feel ashamed of my weight, even as a doctor. But once I understood the science, I realized my body wasn't broken. It was doing exactly what it was designed to do. I just needed the right tools to work with it, not against it.
Medical Treatment Can Help
Today, we have better options than ever before:
Medications
Medications like GLP-1 receptor agonists work by:
Reducing hunger
Improving insulin function
Helping your brain respond to satiety signals
They are not magic pills or injections. But they can make your biology work in your favor.
Bariatric Surgery
For some people, surgery is the most effective tool. It helps by:
Altering gut hormones
Changing how your brain experiences hunger and fullness
Reversing insulin resistance
It's not the easy way out. It's a tool that requires lifelong maintenance.
How to Shift the Conversation
When we treat obesity like the medical condition it is, everything changes:
Instead of "try harder," we say:
Let's understand your biology
Let's create a plan that works for your life
Let's reduce shame and increase support
Instead of judgment, we offer care:
Weight gain is not a moral failure
You are not alone
You deserve real solutions
What You Can Do Today
1. Talk to your doctor.
Ask about medications, referrals, and treatment options.
2. Focus on habits, not just the scale.
Better sleep, stress management, and activity all matter.
3. Learn more about your condition.
Knowledge is power. Understanding how your body works makes change possible.
4. Be kind to yourself.
You are living in a body that is biologically wired to gain weight in a world that makes it easy to do so.
Final Thought
Treating obesity isn't about looking a certain way. It's about reclaiming your energy, your health, and your life.
As a physician who has experienced obesity, I can tell you that it's not your fault. It is your opportunity.
If you're ready to stop fighting your body and start working with it
Dr. Jessica Sanchez-Alfaro is board-certified in Obesity Medicine and Family Medicine. She combines clinical expertise with personal experience to help patients thrive after bariatric surgery and live stronger, longer lives.
🔗 References and Further Reading
The Hungry Brain: Outsmarting"g the Instincts That Make Us Overeat by Dr. St'phan Guyenet
Persistent Metabolic Adaptation 6 Years After "The Biggest Loser" Competition
Fothergill E, "Guo J, Howard L, et al. Obesity (Silver Spring). 2016;24(8):1612–1619.
Why Weight Loss Maintenance Is Difficult
MacLean PS, et al. Obesity Reviews. 2015;16(S1):15–29.
Biological Mechanisms That Promote Weight Regain Following Weight Loss
Dulloo AG, et al. International Journal of Obesity. 2015;39:1188–1196.
Set Point Theory and Genetic Influence on Body Weight
Schwartz MW, et al. Nature Reviews Neuroscience. 2003;4(7):523–532.
Twin Studies in Obesity
Stunkard AJ, et al. New England Journal of Medicine. 1990;322:1483–1487.
Environmental Influences on Obesity
Hill JO, Peters JC. Science. 1998;280(5368):1371–1374.
