Meet Dr. Rosa, nutrition scientist and performance dietitian

Dr. Rosa Keller is a UCSF- and Oregon State University-trained nutrition scientist, dietitian and restaurateur. Today she works with athletes and individuals looking to improve their gut health energy, mood and exercise performance through a whole-foods way of life inspired by her restaurants and family recipes.

  How Rosa Keller, Performance Dietitian and Nutrition Scientist, Can Help You

Services

Work With a Clinical Nutrition Scientist

I offer 1:1 nutrition counseling and gut microbiome testing. If you’re interested in working with me, please fill out this form and book a 15 minute call.

Science

The Science Behind Nutrition & Performance

Learn more about the science of how a nitrates from plants can improve your gut health and exercise performance — ultimately improving your healthspan.

Nutrition Services Across Orange County

Dr. Rosa Keller provides personalized nutrition counseling, gut health programs, and performance-focused nutrition across multiple locations. We proudly serve clients in:
Costa Mesa, Anaheim, Yorba Linda, Orange, Tustin, San Francisco and across Orange County
Whether you’re seeking gut health, sport & fitness, or cardiometabolic nutrition, we bring science-backed guidance to your city.

Science-Backed Nutrition Insights

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Gut Health Guide

Discover the essentials of gut health and learn how to support your microbiome for energy, mood, and overall wellness.

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Best Supplements for Performance

Top 5 supplements that improve athletic performance

Evidence-based guide to the top supplements that improve athletic performance, endurance, and recovery

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Meal Timing for Cardiometabolic Health

Meal Timing for Cardiometabolic Health

Learn how meal timing affects blood sugar, cholesterol, and cardiovascular health based on circadian rhythm science.

Read Article

Delicious Gut-Healthy Recipes

Egg and Labneh Breakfast Toast

A protein-rich, gut-friendly breakfast toast with eggs, labneh, and arugula to boost energy, digestion, and focus.

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A plate of stir-fried greens with chopsticks, with overlaid text about cooking Taiwanese bok choy from Hmart.

Stir Fried Taiwanese Bok Choy

A quick and flavorful Taiwanese bok choy recipe with chili oil that boosts gut health and overall wellness.

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Yu Choy Sum Stir-Fry Recipe

A simple Yu Choy Sum stir-fry recipe designed to boost circulation, energy, and overall vitality naturally.

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Frequently Asked Questions

  • A gut health dietitian specializes in improving digestion, gut microbiome balance, and overall wellness through personalized, whole-food nutrition strategies. They guide clients on diet, supplements, and lifestyle changes to optimize gut health.

  • A healthy gut supports digestion, immunity, metabolism, and mental well-being. Maintaining gut balance can reduce inflammation, enhance energy, and contribute to a longer, healthier life.

  • Gut microbiome testing analyzes the bacteria in your digestive system to identify imbalances. This helps create personalized nutrition plans to improve digestion, immunity, and overall health.

  • Yes! Tailored nutrition based on individual gut health can boost energy, optimize nutrient absorption, reduce digestive issues, and enhance exercise performance for better overall results.

  • Science-backed nutrition provides evidence-based strategies rather than generic diets. By focusing on sustainable, personalized plans, it helps clients maintain gut health, improve metabolic function, and achieve long-term wellness goals.

What clients are saying:

Matt M.

“Rosa is the absolute best! She got very specific to help me get on track for my nutritional and fitness goals. She provided gave me guidance on the right types of food I should be eating. In my case, I was most concerned with protein intake. We worked to find high protein but low calorie options. From there, Rosa worked with me on EXACTLY how many grams I should be consuming per day. We worked to plan my meals around this number. She also recommended tasty options that were in line with my nutritional goals. In addition to that, she recommended WHEN I consume my meals to help me most effectively reach my goals. She even recommended a supplement I take that has worked extremely well for me!”

Lisa S.

“Dr. Keller’s extensive knowledge of nutrition science is truly impressive. She empowers you to take control of your health. She is warm and friendly and creates a comfortable and open space for discussion. Instead of pushing a one-size-fits-all plan, Rosa takes the time to understand individual needs and preferences. She focuses on building sustainable healthy habits rather than quick fixes or restrictive diets. I highly recommend Rosa to anyone seeking a knowledgeable, supportive, and compassionate partner.”

Mari F.

“Working with Dr. Keller over the past several months has been transformative in managing my nutrition and weight. Her patience, attentiveness, and unwavering dedication to my progress, both for short- and long-term goals, are truly unmatched. I feel so grateful to have connected with Fay and to be working with Dr. Keller. If you’re looking to change your perspective on food, health, and wellness for the better, I highly recommend her!”