The Science Behind Why Most Diets Fail (It Has Nothing To Do With You)
Why Most Diets Fail (And What Leptin Has to Do With It)
You start the diet. You’re motivated. You’re eating less, maybe working out more. The scale is finally moving in the right direction. But then… it stops. You feel hungrier. You’re tired. Cravings hit hard. You start slipping — and before long, the weight you worked so hard to lose creeps back on.
Sound familiar?
It’s not a lack of willpower. It’s biology — and one of the biggest hormonal players in this cycle is leptin.
Let’s Talk About Leptin
Leptin is a hormone produced by your fat cells. It acts like a messenger, telling your brain how much energy (aka fat) you have stored. When leptin levels are high, your brain gets the signal: "We're good. You’ve got enough energy stored. You don’t need to eat more."
When leptin levels drop — as they do when you lose body fat — your brain gets a very different message: “We’re starving. Eat more, conserve energy.”
This is where traditional diet culture runs into trouble.
The Diet Trap
When you go on a calorie-restricted diet — especially a significant one — here’s what happens:
Your leptin levels drop because you're losing fat.
Your brain reacts by ramping up hunger and slowing down metabolism.
You feel more tired, more hungry, and less motivated.
You may start craving high-calorie foods — not because you're weak, but because your brain thinks it's saving your life.
Even after the diet ends, your leptin doesn’t bounce back right away. So you're stuck with a slower metabolism and a brain that's still shouting, "We need more food!"
This is why so many people regain the weight — and sometimes even more than they lost.
Why This Hits Harder in Midlife
In perimenopause and menopause, hormonal shifts already impact your appetite, body composition, and metabolism. Add in a restrictive diet, and your body goes into full conservation mode.
This is why the “eat less, move more” advice oversimplifies a very complex situation — and often leaves women in midlife feeling frustrated, defeated, or blaming themselves.
So What Does Work?
The goal isn’t to trick your body into losing weight. It’s to support your body so that it feels safe enough to let go of excess fat — without triggering a hormonal backlash. Here’s how:
Eat enough — especially protein. Protein helps regulate appetite and supports muscle, which keeps your metabolism humming.
Build and maintain muscle. Strength training isn’t just about looking toned — it helps regulate insulin and leptin, boosts metabolism, and improves energy.
Avoid extreme calorie deficits. Slow and steady wins the race. Your hormones prefer consistency and nourishment over restriction.
Sleep and stress matter. Poor sleep and chronic stress mess with both leptin and ghrelin (another hormone that increases hunger).
Focus on habits, not short-term fixes. Think: nutrient-dense meals, hydration, daily movement, and consistency.
The Bottom Line
Your body isn’t broken. It’s doing exactly what it was designed to do — protect you. But if we work with our bodies and not against them, long-term change becomes possible.
So instead of asking, “What diet should I try next?” maybe the better question is:
How can I support my hormones and metabolism so that my body feels safe, strong, and nourished?
That’s where the real transformation begins.