Why Yumiko Left Keto and Improved Her Blood Sugar More Than Ever

Article written and reviewed by Robby Barbaro, MPH
Published June 2, 2026

Meet Yumiko. For years, she believed she was doing everything she could to manage her diabetes.

She carefully watched her blood sugar, adjusted her insulin, and followed a ketogenic diet for nearly a year. Like many people living with diabetes, she had been taught that carbohydrates were the problem and that avoiding fruit, grains, and many plant foods was the safest path forward.

The strategy seemed logical, but despite all of her effort, something was not working.

Her blood sugar numbers continued to drift in the wrong direction, and deep down she knew the lifestyle was not sustainable.

She missed the foods she loved. She worried about the long-term health implications of what she was eating. And most importantly, she felt like she was constantly managing symptoms rather than truly understanding her diabetes.

That search for a better approach eventually led her to Mastering Diabetes.

When Keto Stops Delivering Results

Before joining the program, Yumiko spent about a year following a strict ketogenic diet.

By eliminating most carbohydrates, she was able to reduce some of the immediate blood sugar spikes that had previously frustrated her. But over time, she noticed a troubling pattern.

Her numbers were still creeping higher, even though she was eating very few carbohydrates, her overall blood sugar control was not improving the way she expected.

At the same time, the diet felt increasingly restrictive. Many of the foods she once enjoyed had been eliminated entirely.

Fruit was one of the biggest casualties. Foods like bananas, berries, and other fruits that she loved became foods she feared.

The longer she followed the approach, the more she realized she could not imagine eating this way forever. She wanted a solution that worked long term.

Discovering a Different Way to Manage Diabetes

What initially attracted Yumiko to Mastering Diabetes was surprisingly simple: The food.

The idea that she could eat fruits, vegetables, leafy greens, and whole plant foods again felt liberating. The approach looked healthier, more balanced, and far more sustainable than what she had been doing.

Still, she was skeptical.

After spending so much time avoiding carbohydrates, the idea of eating more of them felt counterintuitive. But she decided to trust the process and give the program a genuine chance.

Almost immediately, she began learning things she had never fully understood before.

Learning That Insulin Management Is About More Than Guesswork

One of the biggest breakthroughs for Yumiko was realizing how much she had been estimating rather than truly understanding her insulin needs.

Before joining the program, she often guessed how much insulin to take before meals. While she understood the concept of carb-to-insulin ratios, she did not always know exactly how many carbohydrates she was eating or how to accurately dose for them.

As a result, her blood sugar would often spike dramatically, with some readings climbing above 300 mg/dL.

Inside the program, she learned how to accurately calculate carbohydrate intake, determine insulin needs more precisely, and understand how different foods affected her glucose response.

The combination of education, tracking tools, and coaching changed everything. For the first time, she felt confident instead of guessing.

Improvements Within the First Week

Yumiko noticed a difference almost immediately.

Within the first week, she began seeing improvements in her blood sugar management. The combination of more accurate insulin dosing and a diet built around whole, nutrient-dense foods started producing results she had not experienced before.

Her glucose became more predictable. She felt more in control. And perhaps most importantly, she no longer felt afraid of food.

Instead of constantly worrying about every meal, she began learning how to work with her body rather than against it.

Yumiko’s Before and After Results

The improvements Yumiko experienced were significant.

Header

Before

After

A1c (%)

7.2

6.0

Fasting Blood Glucose (mg/dL)

150s

Consistently under 100

Insulin Dosage

Inaccurate

Accurate

For Yumiko, lowering her A1c to 6.0 was especially meaningful. She had not seen numbers that low in approximately ten years.

At the same time, her fasting blood sugar dropped from an average of around 150 to below 100, a change she describes as remarkable.

Rediscovering Foods She Thought Were Gone Forever

One of the most emotional parts of Yumiko’s transformation was regaining foods she thought she would never eat again.

For years, fruit had felt off limits. Now, it became part of her daily routine.

Her mornings often begin with large fruit bowls filled with berries and other fresh fruit. She enjoys bananas again, something she never would have touched during her ketogenic years.

She also discovered a new appreciation for leafy greens.

Before the program, salads and greens were not a major part of her diet. Now they are staples.

The combination of fruit and greens became one of her favorite meals and completely changed how she thought about healthy eating.

Instead of restriction, she found abundance.

Better Digestion and Better Daily Life

Another benefit Yumiko noticed was a dramatic improvement in digestion.

Before joining the program, she struggled with chronic constipation. The lack of fiber in her ketogenic diet had created ongoing digestive challenges.

As she increased her intake of fruits, vegetables, legumes, and leafy greens, those issues began resolving.

Her digestion improved significantly, making daily life far more comfortable.

While blood sugar improvements were her primary goal, the digestive benefits became one of the most appreciated side effects of the program.

The Importance of Coaching and Accountability

Yumiko credits much of her success to the education and support she received through coaching.

The weekly coaching calls gave her an opportunity to ask questions, review patterns, and better understand why certain blood sugar fluctuations were happening.

Whenever her numbers spiked unexpectedly, her coach helped her identify possible causes and develop strategies to prevent it from happening again.

Over time, those lessons built confidence. Rather than depending on someone else to manage her diabetes, she learned how to manage it herself. That knowledge became one of the most valuable outcomes of the entire experience.

A Completely Different Relationship With Diabetes

Before joining the program, Yumiko thought she was managing her diabetes well.

Looking back, she realizes she was simply doing the best she could with incomplete information. Today, she feels far more empowered.

She understands how food affects her body. She knows how to accurately dose insulin. She understands how movement, meal timing, and food choices work together to influence blood sugar.

Most importantly, she no longer feels limited by her diagnosis.

What Yumiko Wants Others to Know

Yumiko believes that managing diabetes successfully requires more than simply following rules.

It requires education. It requires consistency. And it requires a willingness to learn.

Her biggest takeaway is that diabetes management is a lifelong skill that can continue improving over time. Once she fully committed to learning the process and applying it consistently, her results improved dramatically.

She now feels equipped with knowledge she can use for the rest of her life.

Ready to See Results Yumiko?

If you're struggling with unpredictable blood sugar, high fasting glucose, insulin dosing challenges, or feel trapped by restrictive diets, Yumiko’s story shows that another path is possible.

Book a free discovery call with one of our advisors and learn how to begin your own transformation.

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About the author 

Robby Barbaro, MPH

Robby Barbaro, MPH is a New York Times bestselling co-author of Mastering Diabetes: The Revolutionary Method to Reverse Insulin Resistance Permanently in Type 1, Type 1.5, Type 2, Prediabetes, and Gestational Diabetes.

Robby was diagnosed with type 1 diabetes at the age of 12 and has been living this lifestyle since 2006. In that time, while eating pounds of fruit every day, his HbA1c has been stable with a current A1c of 5.3%, TIR of 92%, and average total daily insulin use of 30 units.

Robby graduated from the University of Florida and is the cofounder of Mastering Diabetes and Amla Green. He worked at Forks Over Knives for six years before turning his attention in 2016 to coaching people with diabetes full time.

He is the co-host of the annual Mastering Diabetes Online Summit, a featured speaker at VegFest LA, and has been featured on The Doctors, Forks Over Knives, Vice, Thrive Magazine, Diet Fiction, and the wildly popular podcasts the Rich Roll Podcast, Plant Proof, MindBodyGreen, and Nutrition Rounds.

Robby enjoys exercising every day, spending time with friends, and sharing his lifestyle on Facebook, Twitter and Instagram.