Part of his book's summary is absolutely scientifically false. Maybe he was misquoted, but it says this:
"If you are getting adequate calories in your diet, there is no such thing as protein deficiency."
Protein is an essential nutritional component of a healthy diet. Being in protein deficiency is actually painful. But then if you read the quote from the actual book, it has this:
"Protein is not the key to weight loss. Animal protein is not the healthiest food we can eat. Carbs are not the enemy."
That part is true. The key to weight loss is calorie restriction over a sustained period (good rule of thumb: it takes three days of reduced calorie intake).