I eat it on a regular basis. Mono, and in smoothies.
In our years of personal experience, dealing with members, and or research, outside of a treat, we have found that spinach is not really an optimum veggy. Spinach is very high in oxalate acid which is an antinutrient which may actually inhibit the body from absorbing nutrients like calcium and iron. We recommend eating about 1/2-2 heads of lettuce greens a day, and some lettuce greens like romaine still taste great in smoothies.
The following formula works well for long term health and success:
Diet in a Banana Peel
Eat a raw frugivore diet where most carbohydrates and calories come from whole raw ripe sweet and juicy fruits like oranges, papaya, or mangoes, supplemented with about ½-2 heads of lettuce greens a day (not kale, chard, and spinach) and about a handful of raw nuts or seeds a day. Eat simple meals but a rainbow of foods over a period of time.
Eat enough on a daily basis with at least 2500 calories for females and at least 3000 calories for males. Drink 2-4 quarts of water a day and pee clear. Get 8-12 hours of sleep as needed. Exercise about 30 minutes a day 5-6 days a week with at least one day off for rest and repairs. Get about 30 minutes of sunshine a day on your skin for vitamin D, mental health, eye health, and healthy bones and teeth.
For more science behind how to this diet optimally for long term success: