I was introduced to the Keto diet a few years ago. It has helped many people manage their diabetes and even lose lots of weight. There are plenty of guides, recipes, and tips available for people who are just getting started. If you run a keto diet site, you may want to invest in developing custom tools for your audience. Plugins such as Keto Calculator can also help.
This plugin calculates your nutritional needs on a ketogenic diet. It lets you enter data in metric or imperial units to get weight loss and gain plans. It comes with a simple shortcode to include in your pages. You get to view graphs to better understand how much fat and protein should be in your diet.
The developer is planning to add PDF reports and other customization options in the future. No diet calculator is perfect but this plugin could give you ideas on how to develop your own useful diet calculators.