Picture: Okinawa food from Wikipedia
(original food before 1949, commonly not including bread)
Picture: Original Okinawa diet in 1949 (percentage by weight) [ Huffingtonpost ]
Sweet potato is boiled or steamed, not fried.
The rice & grain eg. barley is 'brown ones (not refined)', not 'white ones'.
The original Okinawa food is almost 'plant-based' diet = 98%.
Only 2% from animal foods.
The component is close to the 'G-BOMBS' diet by Dr. Fuhrman.
This diet help control weight & promote immunity ie. [ drfuhrman ]
Table: Nutrition data of sweet potato [ Foods that make you full; Satiety Index ]
Boiled or steamed sweet potato is relatively low calorie food, highly nutritious.
And it makes you full easily (close to potato).
Video: Original Okinawa diet
Pictures: Okinawa food after 1949,
not the old, original diet
Okinawa food for longevity before 1949 is plant-based diet.
The okinawan people like to eat about 80%,
not 100% fullness.
They enjoy social life, meeting friends & relatives.
The lifestyle there is mainly 'do-it-yourself' that makes they move frequently.
May I suggest further reading here.
Have a nice day...
and a healthy life.
From > https://www.researchgate.net/publication/5859391_Caloric_Restriction_the_Traditional_Okinawan_Diet_and_Healthy_Aging_The_Diet_of_the_World's_Longest-Lived_People_and_Its_Potential_Impact_on_Morbidity_and_Life_Span
Photo > By Tomoya Nozaki - originally posted to Flickr as NIBITASHI, https://commons.wikimedia.org/w/index.php?curid=12142094
Photo > By Blue Lotus - Flickr, https://commons.wikimedia.org/w/index.php?curid=1213272
Photo > Public Domain, https://commons.wikimedia.org/w/index.php?curid=122757
Photo > By Laitr Keiows, https://commons.wikimedia.org/w/index.php?curid=8456367