Hand measures as a visual guide for portion size estimation: a)

Healthy Portions: Your hand size can tell you how much to eat

Accuracy of hands v. household measures as portion size estimation aids, Journal of Nutritional Science

Food Portions: Choosing Just Enough for You - NIDDK

Portion sizes using your hand Nutrition infographic, Portion sizes, Portion size guide

Healthy Portions: Your hand size can tell you how much to eat

Portion Sizes - NHS Diabetes

Estimating Portion Sizes With Your Hand: How Much is Enough?

Weight loss stalled? Portion control tools that really work

Hand Portion FAQ: A Guide from Precision Nutrition

Hand Portion Sizes: How To Portion Your Foods Using Your Hands

Ice Cream Scoop & Food Disher Sizes (w/ Size Chart!)

A Handy Guide to Measuring the Sky

A piezoelectric strain sensor mounted below the earlobe.

Accuracy of hands v. household measures as portion size estimation aids, Journal of Nutritional Science