Even occasional substitutions would increase the healthfulness of this diet. For example, sweet potatoes have more nutrients and fiber than potatoes, and far more vitamin A than you get from egg yolks. Wheat and peanuts make complete protein, but brown rice and lentils are even better. A potato has vitamin C, but less than half what you need each day. An orange now and then will help, and a single kiwi has more vitamin C than an orange. Walnuts and avocados have good fats. The point being, please don’t restrict your diet of vegetables, fruits, nuts, grains, and legumes unless you really are living in poverty. And if you’re in the United States, there is help for you–welfare, food stamps, disability benefits, job assistance. No one is expected to live on $2 a day. If you can afford it, vegan, organic food is the healthiest–the best fats, the most vitamins, the most fiber, no cholesterol, no pesticides, good for you and the environment. It’s great to be mindful of poverty and frugal with money, just don’t compromise your nutrition for the sole purpose of taking on a challenge. Otherwise, over time, it could take more than $2 a day to pay your medical bills. If I’m coming across strong, I guess I wanted to counter the strong notion that 5 foods provide a healthy diet for the rest of your life.