Stefani Sassos, M.S., R.D.N., NASM-CPT
Nutrition & Fitness Lab Director
Stefani (she/her) is a registered dietitian, a NASM-certified personal trainer and the director of the Good Housekeeping Institute Nutrition and Fitness Lab, where she oversees all nutrition and fitness-related content, testing and evaluation. She holds a master’s degree in clinical nutrition from New York University, as well as advanced certifications as a Women's Fitness Specialist and a Behavior Change Specialist. Stefani is dedicated to providing readers with evidence-based content to encourage informed food choices and healthy living. She is an avid CrossFitter and a passionate home cook who loves spending time with her big fit Greek family.
- Topic Specialties
Latest from Stefani Sassos, M.S., R.D.N., NASM-CPT

8 Best Neck Massagers for Instant Tension Relief
We tested over a dozen neck massagers and these picks stood out for their effectiveness, comfort, and overall value.

I Tested NordicTrack's New Pilates Reformer—and It Might Be the Peloton of Pilates
$5K for a reformer—worth it? I had to find out.

What Is Grass-Fed Beef, and Is It Better for You?
The term “grass-fed” can be confusing. Here’s what it does—and doesn’t—mean about your next burger or steak.

The 6 Best Dumbbells for Building Strength, According to a Personal Trainer
Top-tested picks for beginners, home gyms, and serious lifters.

I'm a Dietitian—Here's My Honest Review of the Viral Vital Proteins Collagen and Protein Shake
I think this may be the easiest way to take collagen.

Is There a Best Time to Take Vitamin B12? Experts Explain
There is a time of day you might want to prioritize it.

10 Best Magnesium Supplements, According to Registered Dietitians
From gummies to capsules to liquids, we vet the best ways to meet your daily magnesium intake.

Dietitians Swear by These 13 Super-Healthy Fruits
It's hard to pick a top contender when all of these are packed with health benefits.

The New Rules of Grilling
Whether you're feeding the family or hosting a backyard crowd, these techniques, tools, and recipes will help you cook with more confidence all season long.

8 High-Protein Tinned Fish You Should Be Eating, According to Dietitians
Sardines are on the list, but there are more delicious options to explore.

11 Best Healthier Coffee Creamers, According to Nutrition Experts
The healthiest and tastiest options.

Dietitian-Approved Bars & Bites That Actually Taste Amazing
Discover the best snack bars and bites, approved by dietitians and taste testers in Good Housekeeping’s 2026 Snack Awards.