What patients are saying
Overall rating
5.00
Average wait time
5.00
Bedside manner
5.00
“I had a great experience working with issac. He was knowledgeable, supportive, and took the time to understand my individual needs and goals. His recommendations were realistic, easy to follow, and tailored to my lifestyle rather than being overly restrictive. I felt encouraged throughout the process and appreciated his professional yet approachable attitude. I would definitely recommend him to anyone looking for guidance on their health Journey.”
Initials hiddenJuly 6, 2026Video visit
“Isaac is great! It really seems like he “gets it” and he has an impressive, multidisciplinary knowledge. He was delivering breakthroughs as early as our first session!”
BPLess than 1 year ago
About Isaac Diaz
***PLEASE READ: To help us provide the best care to all patients, please book an appointment only if you're committed to working toward your nutrition or fitness goals. The best results often come with ongoing care and follow up visits. Late cancellations and no-shows limit access for others seeking care. We're happy to work with you if an emergency or unavoidable circumstance arises. Thank you for your understanding. -Please verify your insurance plan BELOW. Please DOUBLE CHECK the full plan name on your insurance card BEFORE booking. Thank you!***
UnitedHealthcare (UHC): PLEASE confirm your plan is NOT listed below as we do NOT accept:
- "HMO" (NOTE: We often see HMO plans booked as POS plans.)
- Student Resources Plans (HMO, PPO, POS, or EPO)
- Medicare Advantage, Medicaid, or government-funded plans
Aetna & Meritian Health: If your full plan name does not include the words "Open Access/Open Choice" or "Choice POS II", we DO NOT accept it. PLEASE VERIFY by reading the FULL plan name on your insurance card. We ONLY accept these 5 exact plan names:
1. "OPEN Choice" (PPO)
2. "CHOICE POS II"
3. "Select OPEN ACCESS" (EPO)
4. "Elect Choice OPEN ACCESS" (EPO)
5. "Managed Choice OPEN ACCESS" (POS)
**Tired of starting over with your weight and fitness goals and ready to maximize your nutrition, fitness, and habits in a sustainable way?
I help clients with their weight goals, improve body composition, build healthier habits, and create realistic routines they can maintain long term — without restrictive dieting.
My approach combines evidence-based nutrition, behavior change coaching, accountability, and practical strategies tailored to real life.
Together, we work on:
- Weight and sustainable habit change
- Fitness and body composition goals
- Emotional eating and cravings
- Meal planning and high-protein nutrition
- Building consistency and motivation
- Nutrition to support exercise performance and recovery
Let's get started together!
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In-network insurances
99% of patients have successfully booked with these insurances
Aetna
BlueCross BlueShield
UnitedHealthcare
Popular visit reasons
New Patient Visit
Nutrition Consultation
Obesity / Weight Loss Consultation
Obesity Nutrition Consultation
Sports Nutrition Evaluation
Underweight Nutrition Consultation
Weight Loss Consultation
Weight Management
New Patient Visit
Nutrition Consultation
Obesity / Weight Loss Consultation
Obesity Nutrition Consultation
Education and background
Practice names
Board certifications
- Commission on Dietetic Registration
- Registered Dietitian (RD) (Commission on Dietetic Registration)
- Registered Dietitian Nutritionist (RDN) (Commission on Dietetic Registration)
Education and training
- California State University, San Bernardino, Bachelor's in Food and Nutrition Science
- California State University, San Bernardino, Master's in Public Health
Languages spoken
- English
- Spanish
Provider's gender
Male
NPI number
1386402188
Patient reviews
All reviews have been submitted by patients after interacting with the practice.
Overall rating
5.00
Wait time
5.00
Bedside manner
5.00
Your trust is our top concern, so providers can't pay to alter or remove reviews. We also don't publish reviews that contain any private patient health information. Learn more here
22 reviews
Most relevant
Issac provided a good foundation for nutrition. Would recommend for anyone wanting to eat better and feel better.
Less than 1 year agoPP
Isaac was very personable, he answered my questions and I have high hopes for our next session.
Less than 1 year agoDP
Isaac Diaz is knowledgeable and an excellent listener. I would definitely recommend him.
Less than 1 year agoMT
Very professional and very friendly while explaining things that are completely understand
Less than 1 year agoHH
I learned a lot! I can’t wait to learn more about nutrition and ways to improve my health.
More than 1 year agoSS
Isaac was professional and helpful in all sessions
More than 1 year agoAV
I had a great experience working with issac. He was knowledgeable, supportive, and took the time to understand my individual needs and goals. His recommendations were realistic, easy to follow, and tailored to my lifestyle rather than being overly restrictive. I felt encouraged throughout the process and appreciated his professional yet approachable attitude. I would definitely recommend him to anyone looking for guidance on their health Journey.
July 6, 2026Initials hiddenVideo visit
Isaac is great! It really seems like he “gets it” and he has an impressive, multidisciplinary knowledge. He was delivering breakthroughs as early as our first session!
Less than 1 year agoBP
I am very pleased with the work I have done with Isaac. He listens and provides manageable steps and actions you can take to meet your goals. He shares knowledge so that you can make good decisions and choices on the way to a healthier lifestyle. Highly recommend!??????
Less than 1 year agoDH
He was very welcoming and friendly, yet professional. Definitely felt like he was there to support me and my goals in the best way possible. Highly recommend him to anyone especially for athletic goals!
Less than 1 year agoDC
Seeing Isaac as a dietitian was a great decision. He was very easy to talk to, and appreciated my honesty and bluntness. He listened to my concerns, and offered realistic solutions and advice. I know my body and some of what works for me (and what probably doesn’t). I know I don’t always make the best choices with my diet. But he never judged me for that. He was professional and helpful during our conversation—so much so, that it felt like I was talking to a friend or coworker. I highly recommend him as a dietitian.
August 20, 2025William C.Verified patientVideo visit
My appointment with Isaac was great! He asked me so many questions and he could
Identify the mistakes was doing in my diet. He answered all my questions and elaborated a very good plan for me to loose weight. I can’t wait for next visit. Thanks.
Less than 1 year agoSF
Dr. Isaac was very friendly and took the time to listen to my concerns and needs. I learned a lot from him and about myself during the appointment and I appreciated his grace-based approach to nutrition, health and fitness.
August 11, 2025Katlyn S.Verified patientVideo visit
Good listener and knowledgeable
Less than 1 year agoJF
Issac is great to talk with. He is easy going and can relate.
He took the time to address all of my questions. I especially liked thathe took notes so that he didn't miss any points in my multiple part questions.
Less than 1 year agoAD
Isaac is a great clinician. Personable and understanding, his approach to diets is small meaningful changes to better for choices. He takes into account his clients' living situation and conditions to tailor the best approach to reach attainable goals and remembers the little details over sessions making his bedside manner more akin to a foodie friend than a doctor treating yet another patient.
More than 1 year agoJB
I really liked working with Isaac! It was really helpful to have an audit of my eating habits, and I learned a lot over the course of my visits!
More than 1 year agoGL
Issac was very professional and listened to my wants and needs. Which in turn, helped us make actionable goals to strive for. He further provided me with useful resources that helped me track my diet so I could stay consistent and have a record to refer back to!
More than 1 year agoCC
Less than 1 year agoInitials hidden
Less than 1 year agoInitials hiddenVideo visit
More than 1 year agoJR
More than 1 year agoCH
How soon can I make an appointment with Isaac Diaz?
Generally, Isaac Diaz has appointments available on Zocdoc within 1 week. You can see Isaac Diaz's earliest availability on Zocdoc and make an appointment online.
Is Isaac Diaz accepting new patients?
Isaac Diaz generally accepts new patients on Zocdoc. You can see Isaac Diaz's earliest availability on Zocdoc and schedule an appointment online.
Does Isaac Diaz accept my insurance?
Choose your insurance plan to verify if Isaac Diaz is in-network.
Can I make an appointment with Isaac Diaz online?
Yes, you can make an appointment online with Isaac Diaz using Zocdoc. It’s simple, secure, and free.
What practice does Isaac Diaz work with?
Isaac Diaz works with Fit4Life Nutrition.
Which board certifications does Isaac Diaz have?
Isaac Diaz is certified by Commission on Dietetic Registration, Registered Dietitian (RD) (Commission on Dietetic Registration), and Registered Dietitian Nutritionist (RDN) (Commission on Dietetic Registration).
What are common reasons for patients to see Isaac Diaz?
Isaac Diaz frequently sees patients for New Patient Visit, Nutrition Consultation, Obesity / Weight Loss Consultation, Weight Loss Consultation, and Weight Management. You can see other visit reasons for Isaac Diaz on their profile.
What languages does Isaac Diaz speak?
Isaac Diaz speaks English and Spanish.
How do patients rate Isaac Diaz in reviews?
22 patients have reviewed Isaac Diaz. The overall rating for this doctor is 5/5. They have a 5/5 rating for bedside manner and a 5/5 rating for wait time. You can read individual reviews and ratings on their profile.