All the more proof this guy has no idea what he is talking about when it comes to diet. For someone who has wrote a book called Grain Damage, he looks as if he is making it up as he is going along.
Grains and starches aren't my favorite foods either, but he could have at least came up with decent reasons for avoiding these foods such as the celiac/gluten aspect or that many are intolerant to these foods.
Yet he comes away with very poor reasons such as lack of vitamin C or that some add oils/fats to these starchy foods. Not all cooked starch rich foods are grains either, there are the starchy root vegetables such as carrots, sweet potatoes and even peas for example. These are perfectly healthy foods for the majority, infact they contain more nutrition pound for pound than most of the fruits that Doug Graham recommends to eat so much of. Banana's, watermelon and such are typically low nutrient foods, certainly not foods you would want to base your diet around.
Basically what he is saying is that we should only eat sweet foods such as fruit, nothing savory. His advice is to starve yourself and keep missing meals until fruit is appealing again. Which is terrible advice overall for health and more likely to make someone reach for a quick fix junk food. Sounds like hes got a raging sweet tooth from the way he talks about needing to keep coming back to sweet foods. Many individuals do perfectly fine without needing to consume excessive amounts of simple sugars.
Whilst eating fruit is healthy for most within a balanced diet, basing your diet around only one food group i.e fruit in this case is one of the worst things you can do for health. I have no doubt that Doug Graham eats more than he lets on. For example he believes that we can get our Vitamin B12 from breathing the air, if he is indeed just eating fruits and vegetables, he would be getting no dietary Vitamin B12 intake.