In addition to addressing the issues of nutrition education, availability of healthy options and accessible technology there are other factors that play into what and how we eat that could be addressed.
Parenting difficulties. It's tough to get children (and ourselves) to eat healthy food. We are bombarded with enhanced images of unhealthy foods that look like they are way more fun than veggies. Sodas, candy, chips, pizza, fast food burgers etc. Fruits and Veg don't get the same treatment and they are a hard sell at the dinner table. And those other foods are easier to serve and at least guarantee that picky eaters will eat.
Emotional eating habits. There is a reason it's easier to develop a habit of eating junk food. It's a fast way to satisfy an emotional hunger. Chips, candy, soda, popcorn. The sugar and salt and the repetitive motion of putting food in your mouth repeatedly brings more satisfaction than a balanced meal.
Maybe the solutions could incorporate answers to these two issues.
1. Healthy food needs a good PR rep in the house. We need to stop presenting veggies as "good for you" requirements and sweets as "yummy treats."
"It’s counterintuitive, but the way to teach children to eat healthy foods is to stop talking about how healthy the food is. Instead, we have to change the conversation to habits." How Smart Parents Teach Their Kids Unhealthy Eating Habits - Post published by Dina Rose Ph.D. on Sep 22, 2014 in The Art & Science of Teaching Kids to Eat Right https://www.psychologytoday.com/blog/the-art-science-teaching-kids-eat-right/201409/how-smart-parents-teach-their-kids-unhealthy
2. If we are not eating because we are hungry we won't stop when we are full. I had a minor issue with emotional eating a few years back and it took a long time to build up enough awareness and the tools to deal with my strongest emotions before I could stop "eating to feel better." There are plenty of apps that will create grocery lists of healthy meals but if you're depressed or angry in front of the refrigerator that app won't be much help.
Incorporating personalized questions about feelings and eating habits may help people build awareness around emotional eating. Questions like - When are you most likely to overeat or eat things you later regret? I noticed you ate a lot of sugar yesterday - how were you feeling? Angry? Sad?
An app that has a bit of a personality (or several available personalities) can be a support for the user. If the app learns that user Sara is a late night binger, it can schedule an alert to remind Sara to check in with her feelings and write about them or talk to a friend instead of eating. The suggestions can be simple or more robust with links to available therapies, online resources or even healthier food replacements. (See http://psychologyofeating.com/simple-psychology-habits/)
Technology can't give us the love/happiness we may be trying to find in a bag of chips and it can't force our children to choose an apple over a candy bar but it can be designed around these two very human frailties.