Nutritionists & Dietitians

Custom Fit Registered Dietitian: Tara Venn

Tarah Valenti, RDN

Director of Nutrition | Registered Dietitian | Owner

My background in nutrition started in the sports world. I grew up with an athlete as a father and watching him nourish and train his body for performance taught me the power of nutrition on performance outcomes. When I went to college, I discovered my passion for human biology and disease prevention through behavior change. This lead me to dive deeper into science and medicine, pursue an education in nutrition and become a registered dietitian. Through my experiences working in clinical research and private practice I continue to be amazed at what the human body and mind are capable of. I love working with people to discover new ways to improve their health, eliminate barriers and enhance their overall wellbeing and sense of empowerment. I sincerely believe that we can all unveil a brighter, happier self with the power of nutrition and delicious food!

Certifications & Education

San Francisco State University - Bachelor of Science, Dietetics

Cornell University - Dietetic Internship

Commission on Dietetic Registration, Academy of Nutrition and Dietetics - Registered Dietitian

Certified Bone Densitometry Technologist (CBDT)

National Academy of Sports Medicine (NASM) - Certified Personal Trainer

Contact:

Email: Tarah@customfitsf.com


Nutritionist and Owner: Marissa Mather

Marissa Mather

Nutritionist | Owner

Food and cooking has been a lifelong passion of mine. Growing up, my mother was a dietitian, so we always had an emphasis on eating healthy and balanced meals. My Greek background allowed me to learn a lot about the Mediterranean diet as well as the importance of enjoying meals with family and friends. Born and raised in the Bay Area, I love learning and being immersed in the inspiring and innovative food scene that we are world famous for. Before studying to become a nutritionist I worked in the restaurant industry for 10 years, so my passion for food is not only focused on health, but being delicious as well! I love learning, researching, and testing new recipes that utilize local and seasonal ingredients, are easy to make, and most importantly taste great. I truly believe that healthy, nourishing food can be enjoyable and designed to fit into everyone’s lifestyle, regardless of time, finances or skill.

Certifications & Education

Bauman College - Certified Nutritionist

Certified Bone Densitometry Technologist (CBDT)

California State University Chico - Bachelor of Arts, International Relations

Contact

Email: Marissa@customfitsf.com


Kai Samiere, RDN

Registered Dietitian - Sport Nutrition | DEXA Technician

The more I learn about nutrition, the more I realize how foundational food is in living a balanced life and performing your best. With so much misinformation on the internet and social media, it's become impossible to decipher what's right, wrong or somewhere in between. My goal is to use evidence-based research to help those around me unlock their maximum potential through the power of nutrition and consistency.

Entering my first year of college, I wasn't sure where I could take a degree in nutrition. But, after an internship with Stanford's Sports Nutrition team, and seeing the power of nutrition in sport, I knew that I wanted to pursue a career in sports dietetics. As an avid surfer, I've been able to use my knowledge and experience to improve my own eating habits around performance and daily living. Along with consistent training, mindful practices like yoga and meditation, and a balanced approach to eating, I am seeing improvements both in and out of the water. 

I believe that when we nourish and treat our bodies well, we get the most out of ourselves. So no matter the sport or hobby, whether you want direct coaching, nutrition education or just want to talk about food, I truly look forward to connecting and helping you reach your goals.

Certifications and Education:

California Polytechnic State University - Bachelor of Science, Nutrition

Merrimack College - Master of Science, Health and Wellness Management

Wellness Workdays - Dietetic Internship, Sports Nutrition & Entrepreneurship

Commission on Dietetic Registration, Academy of Nutrition and Dietetics - Registered Dietitian

University of California San Diego - Certified Bone Densitometry Technologist (CBDT

Contact:

Email: kai@customfitsf.com


Summer Williams, RDN

Registered Dietitian | Personal Trainer | Health Coach

My passion for nutrition began during my time as an acrobat in Cirque du Soleil. Before retiring, I became a personal trainer and health coach, and then moved to Australia. 

Over the following years, I realized the immense benefit of combining nutrition with fitness to help my clients achieve their goals. 

Upon returning to the states, I worked in various established gyms and in corporate fitness, before starting my own personal training and health coaching business.

Simultaneously, I pursued a degree in Nutrition from San Francisco State University. As a Registered Dietitian, I believe in a holistic health approach. It is important to address not only nutritional needs but also to consider the broader aspects of well-being - physical, mental, and emotional. I feel that everyone can benefit from improved nutrition, whether it’s for improved performance or overall well-being. 

Certifications & Education

San Francisco State University - Bachelor of Science, Dietetics

San Francisco State University - Dietetic Internship

Commission on Dietetic Registration, Academy of Nutrition and Dietetics - Registered Dietitian

National Academy of Sports Medicine (NASM) - Certified Personal Trainer

National Academy of Sports Medicine (NASM) - Virtual Coaching Specialist

American Council on Exercise (ACE) - Certified Health Coach

Contact:

Email: summer@customfitsf.com


Alysha Coughler, RDN

Registered Dietitian | Personal Trainer

Hello, I’m Alysha, a Registered Dietitian, personal trainer, and motivational coach with a deep-rooted passion for food and movement. Growing up on a farm, I learned about the origins of the food on our table and spent hours in the kitchen with my grandmother.

When I became ill in high school, my perspective shifted, and I began to see food as medicine, recognizing its ability to energize and support our bodies. I now love modifying recipes to meet different dietary needs, proving that nutritious food can also be delicious.

My practice today combines my experience as a dietitian with my background in personal training to guide clients toward their performance goals. My own love of movement began with weightlifting during undergrad, and I’m currently enjoying the world of triathlons.

My approach focuses on delivering evidence-based nutrition strategies, promoting optimal physical performance, and fostering a strong, positive relationship with food and movement.

I take a holistic approach to counseling, focusing not just on nutrition but also on movement, sleep, stress management, and hydration. My goal is to empower you to make food you love an integral part of a balanced and fulfilling lifestyle. Together, we’ll work toward overcoming any barriers and creating a path to optimal health and wellness.

Certifications & Education

University of Guelph - Bachelor of Applied Science, Human Nutrition

University of Guelph - Personal Training Specialist Certification 

Toronto Metropolitan University - Master of Health Science in Nutrition Communication + Dietetic Internship 

Commission on Dietetic Registration, Academy of Nutrition and Dietetics - Registered Dietitian 

Contact:

Email: alysha@customfitsf.com