Dr. Michael Diamonds has seen a troubling pattern emerge among disciplined women trying to lose weight through fasting.
Despite their commitment and effort, they hit frustrating plateaus that seem impossible to break through.
The medical doctor, scientist, and pro-natural bodybuilder has coached nearly thousands of women at his company, Sculpt by Science, and discovered something critical: fasting isn’t broken, but the aggressive approach most women take works against their biology.
In a recent video, Diamonds shared his “progressive fasting” system—a method that’s helped women from their 20s through their 50s finally achieve sustainable fat loss, including his own mother who lost 40 pounds using this exact approach.
Jump to:
- The Metabolic Trap Most Women Fall Into
- The Two Hormones That Make or Break Female Fat Loss
- The Real Benefits of Properly-Executed Fasting
- The Progressive Fasting Solution: Five Strategic Stages
- Why Progressive Fasting Avoids Metabolic Shutdown
- Eliminating Food Noise Through Biochemistry
- The Path Forward for Women Over 35
The Metabolic Trap Most Women Fall Into
Diamonds describes a predictable cycle he witnesses constantly. A woman decides to lose weight and immediately jumps into 16:8 fasting—eating her first meal at noon and last meal at 8 p.m., eliminating breakfast entirely.
Week one brings encouraging results. A few pounds drop off, energy feels good, and the approach seems promising.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
But by week three, progress stalls completely. The natural response? Double down. Add two more fasting hours, moving to an 18-hour fast. Drop calories even lower, maybe down to 1,100 calories daily in a tiny eating window.
You’re starting to blame your body, and you think you’re failing, but you’re not failing. It’s the approach that is failing you.
According to Diamonds, this aggressive strategy triggers specific hormonal responses in women that completely shut down fat loss.
The Two Hormones That Make or Break Female Fat Loss
Cortisol: The Anti-Testosterone Effect
Diamonds calls cortisol “anti-testosterone”—and while women don’t produce as much testosterone as men, they still need it for building muscle, boosting metabolism, and burning fat.
Cortisol does the exact opposite. It breaks down muscle tissue, slows metabolism, and specifically stores fat around the belly.
The science backs this characterization. Research on hormonal cross-talk shows cortisol suppresses gonadotropin releasing hormone (GnRH) from the hypothalamus—the signal that initiates testosterone production. Less GnRH means less testosterone, period.
At the cellular level, cortisol and testosterone compete for the same receptor sites. When cortisol floods the system during aggressive fasting, it occupies those receptors first, blocking testosterone’s muscle-building and fat-burning signals from being delivered.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Even worse, cortisol activates the ubiquitin proteasome system—cellular machinery that systematically tags and breaks down muscle protein for fuel.
Here’s the critical part for women specifically: research shows women are significantly more sensitive to the metabolic effects of cortisol than men. The same cortisol level does far more damage to a woman’s fat-burning hormones, thyroid function, and reproductive hormone cascade.
Your body evolved to be exquisitely sensitive to energetic stress because it needs to assess at all times whether it has enough resources to sustain life. That’s a protective mechanism. But when chronic stress meets aggressive fasting, that sensitivity becomes a trap.
The Cortisol-Insulin Vicious Cycle
When women jump straight into aggressive fasting protocols, their bodies read the dramatic energy restriction as a threat. The HPA axis (hypothalamus-pituitary-adrenal stress command center) fires, cortisol floods in, and the body enters fight-or-flight mode.
In fight-or-flight mode, bodies don’t burn fat—they hoard it.
Cortisol tells the liver to manufacture glucose from muscle tissue through gluconeogenesis. Blood glucose rises, triggering insulin release from the pancreas. And insulin—a storage hormone—immediately shuts down lipolysis, the breakdown of fat.
Fat literally cannot leave fat cells when insulin is elevated.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
You’re fasting to lower insulin and burn fat. But the aggressive fast spikes cortisol. Cortisol raises insulin. Insulin locks fat. You’ve cancelled out the entire point of why you’re fasting in the first place.
Additionally, cortisol directly activates alpha-2 adrenergic receptors on abdominal fat cells, which actively resist fat mobilization. Research by Lafontan and colleagues published in Endocrine Reviews identified these receptors as the primary reason women under chronic stress accumulate stubborn belly fat.
Cortisol also impairs conversion of thyroid hormone T4 into its active form, T3—your metabolic thermostat. When T3 drops, resting calorie burn plummets.
Understanding Insulin: The Librarian Analogy
Diamonds uses a brilliant analogy to explain insulin function. Think of insulin as a librarian whose job is taking books (glucose from food) and filing them on the right shelves: muscle, liver, and brain.
When books arrive at a manageable rate, the librarian stays efficient and organized. But when too many books flood in at once—from constant eating and snacking across 14-16 hour windows—the librarian gets overwhelmed and starts sweeping books under the rug.
The rug is your fat tissue.
Fasting gives the librarian a break. When eating stops, glucose stops coming in, insulin drops, and the librarian can finally retrieve those books from under the rug and use them as fuel.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
This is the entire mechanism of fat loss through fasting: low insulin unlocks stored fat.
Research published in Cell Metabolism showed significant reductions in fasting insulin within just two weeks of structured fasting protocols, with lower insulin meaning fat cell doors swing open.
The Real Benefits of Properly-Executed Fasting
When done correctly—without spiking cortisol—fasting unlocks powerful metabolic benefits specifically valuable for women over 35.
Insulin Suppression
Low insulin creates the foundation for fat burning. Research shows even modest extensions of overnight fasts—moving from 12 to 14 hours—measurably improve insulin sensitivity in women.
A study in Cell Reports Medicine demonstrated that 14:10 fasting (first meal at 10 a.m., last meal at 8 p.m.) significantly reduced insulin levels and improved fat burning specifically in women.
Autophagy: Cellular Anti-Aging
Autophagy is the body’s natural cellular cleaning system—cells literally break down and recycle damaged components, old proteins, and cellular debris.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Research shows autophagy triggers around the 14-16 hour fasting mark. This anti-aging, anti-inflammatory benefit doesn’t occur with standard caloric deficits alone.
Growth Hormone Pulsing
A classic study in the New England Journal of Medicine showed fasting can increase growth hormone from 300% to 2,000% over baseline levels.
Growth hormone is a muscle-preserving, fat-burning hormone. Proper fasting protects lean mass while accelerating fat loss—you’re recomposing, not wasting away.
Natural GLP-1 Production
The body produces GLP-1 naturally during extended fasts. This is the same hormone medications like Ozempic mimic.
Research confirms fasting elevates endogenous GLP-1, which slows gastric emptying, reduces appetite, and creates genuine satiety. Progressive fasting delivers the natural version of this effect.
Reduced Inflammation
When the digestive system gets rest from constant food intake, inflammatory markers drop—specifically C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha).
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
For women over 35 dealing with hormonal inflammation, this represents a game-changing benefit backed by consistent research across fasting protocols.
The Progressive Fasting Solution: Five Strategic Stages
Diamonds uses a powerful visual metaphor: your stomach is a balloon. If you’ve been eating across long windows with multiple meals and snacks, your stomach has physically expanded to accommodate that volume.
Try to deflate a balloon too fast, and it snaps back. This is exactly what happens when jumping from a 14-hour eating window straight to a 6-hour window.
The hunger you feel when you go straight to the 16:8 or 18:6 is not a willpower problem. It is a physical signal from a stomach that has not been given time to adapt.
Progressive fasting deflates the balloon naturally. The stomach physically adapts to smaller volumes, stretch receptors recalibrate, and ghrelin (the hunger hormone) resets over weeks.
The golden rule: only move to the next stage when the current stage feels genuinely manageable.
Stage 1: 12:12 Fasting
- Window: First meal at 8 a.m., last meal at 8 p.m.
- Calories: 1,800-2,000+
- Purpose: Stop snacking and grazing; establish eating boundaries
This stage simply puts parameters around eating. The library opens at 8 a.m. and closes at 8 p.m.—no books accepted outside those hours.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Stage 2: 14:10 Fasting
- Window: First meal at 10 a.m., last meal at 8 p.m.
- Calories: 1,600-1,800
- Purpose: Extend overnight fast to trigger fat-burning metabolism
Research confirms that around the 13-14 hour mark, liver glycogen stores begin depleting and the body shifts to fat as its primary fuel source. You’re becoming a fat-burning machine every morning.
Because you spent weeks in Stage 1, the stomach has adapted. Hunger at 8 a.m. has diminished naturally—no white-knuckling required.
Stage 3: 16:8 Fasting
- Window: First meal at noon, last meal at 8 p.m.
- Calories: 1,400-1,600
- Purpose: Trigger autophagy and growth hormone benefits
This is the classic 16:8 protocol—but with a crucial difference. You didn’t jump here; you earned it.
Your stomach is smaller, ghrelin has reset, cortisol stays calm, and you’re arriving with metabolism intact rather than suppressed. At 16 hours, autophagy reliably triggers, cells clean house, and growth hormone pulses to protect muscle while burning fat.
Stage 4: 18:6 Fasting
- Window: First meal at 2 p.m., last meal at 8 p.m.
- Calories: 1,200-1,400
- Purpose: Deep cellular repair and stubborn fat mobilization
Autophagy runs at full force here. Anti-inflammatory benefits intensify. Most excitingly for Diamonds’ clients: stubborn belly fat finally starts moving.
Remember those alpha-2 adrenergic receptors on abdominal fat cells that cortisol activates? With cortisol low because you arrived here progressively, those receptors aren’t being stimulated. The door on belly fat opens.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Research on fat metabolism confirms that lower sympathetic stress and reduced cortisol directly improve lipolysis in abdominal fat deposits.
This is the stage where Sandra, Ashley, and Annabelle started messaging me, Dr. Mike, I am seeing the outline of my abs.
Stage 5: 20:4 Fasting
- Window: First meal at 4 p.m., last meal at 8 p.m.
- Calories: 1,100-1,300
- Purpose: Peak fat burning for visible six-pack definition
Diamonds emphasizes most women don’t need this stage—it’s specifically for those pursuing complete six-pack visibility. He doesn’t keep clients here long, typically just the final four weeks when eliminating the last stubborn fat.
What surprises every woman reaching this stage? They’re not starving or miserable. They’re genuinely not hungry because the stomach has adapted naturally over months.
Research by Stubbs and colleagues published in the Journal of Obesity showed that beta-hydroxybutyrate—the ketone produced during extended fasting—lowers ghrelin levels and directly suppresses hunger signals.
The brain runs on clean, efficient fuel and registers satisfaction despite objectively significant caloric deficits.
Why Progressive Fasting Avoids Metabolic Shutdown
When calories drop aggressively—say from 2,000 to 1,000 overnight—the body triggers adaptive thermogenesis. Studies in the New England Journal of Medicine show metabolic rate can drop 20-30% beyond what weight loss alone would predict.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Everything downregulates: resting calorie burn plummets, movement decreases, fidgeting stops, and non-exercise activity thermogenesis (NEAT) drops dramatically. People stop doing small tasks like putting dishes away or tidying up—the body conserves every possible calorie.
This is what Diamonds sees in women arriving at Sculpt by Science eating 900 calories daily yet unable to lose weight. They’ve trained their bodies to survive on almost nothing, and 900 calories has become their maintenance level.
Progressive fasting never triggers this emergency response because changes happen gradually. The body never registers a crisis, the HPA axis stays quiet, the “librarian” keeps working efficiently, and thyroid function continues converting hormones properly.
By the time women reach Stage 5 eating 1,100-1,300 calories, their bodies arrived there together—still burning efficiently rather than shut down in survival mode.
Eliminating Food Noise Through Biochemistry
One of the most frustrating aspects of traditional dieting: constant food obsession. The inability to focus because thoughts circle endlessly around eating.
This isn’t weak willpower—it’s biology. When eating small amounts across many meals, ghrelin peaks before every meal. Six small meals means six hunger peaks throughout the day, creating constant anticipation mode.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Progressive fasting reorganizes these hunger signals. As the eating window compresses gradually, ghrelin learns to pulse within that window rather than throughout the entire day. Outside the window, signals quiet down.
In deeper fasting stages, natural ketone production elevates. Research confirms beta-hydroxybutyrate reduces ghrelin and hunger signals biochemically—not through discipline or white-knuckling, but through actual changes in hormone signaling.
This creates the version of fat loss that’s actually sustainable long-term because women aren’t fighting biology every single day.
The Path Forward for Women Over 35
Diamonds maintains the science supporting fasting is overwhelming and undeniable. But the aggressive approach most women take—jumping straight to restrictive windows and slashing calories—triggers cortisol that cancels every benefit.
The anti-testosterone effect floods in, muscle breaks down, the librarian gets overwhelmed and sweeps glucose under the rug (into fat tissue), belly fat locks away, and metabolism slows.
Women end up in a metabolic straitjacket: eating almost nothing while burning fewer calories, wondering what’s fundamentally broken in their bodies.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Progressive fasting offers an intelligent alternative built on gradual adaptation:
- Stage 1 (12:12) stops grazing and gives the digestive system boundaries
- Stage 2 (14:10) begins fat-burning metabolic shifts
- Stage 3 (16:8) triggers autophagy, growth hormone, and natural GLP-1
- Stage 4 (18:6) delivers deep cellular repair and unlocks stubborn belly fat
- Stage 5 (20:4) provides peak fat burning for complete definition
Every benefit of fasting becomes accessible—earned properly without spiking cortisol. Small, science-based changes compound into transformative results by working with female biology instead of against it.
For women over 35 who’ve tried aggressive fasting and hit frustrating plateaus, Diamonds’ progressive approach offers a scientifically-grounded path that respects hormonal sensitivity, protects metabolism, and delivers sustainable fat loss that finally sticks.
