I've actually taken this from the medical rehab facility that my mom recently recovered at. Dinner-type (quality/quantity) meals were served at lunchtime and lunch-type meals at dinner. For instance, the mid-day meal could be baked chicken, mashed potatoes w/gravy, mixed vegetables and roll, while the evening meal could be a sandwich and chips.
I always had a hard time getting mom to eat enough at dinner because she was wearing down (energy, mobility) and usually on the verge of sun-downing. With the switch, she enjoys the heavier noon meal that fuels the rest of her day and is more willing to consume the lighter faire, later in the day. Bonus - we're BOTH less stressed at bedtime!