title: Rails - 1 entry in model per field, per day
body: <p>Lets say I have a food model</p>
  
  <p>in the model, every day, people enter how many lbs of pizza/vegetables/fruit they eat.</p>
  
  <p>each food is its own column</p>
  
  <p>my issue is, I'd like it so they can only enter that in once (for that food type) every 24 hours (based on created_at).</p>
  
  <p>This possible?</p>