As a personal trainer and nutrition expert I would tend to agree with you here. Too much vague information that doesn't apply to every person's metabolic type. We all have varying metabolic types, here is an OK article explaining what metabolic typing is: http://www.beyond-diet-reviews.com/how-to-determine-your-metabolic-type/
After a 10 minute search I could not fine any scholarly articles on the subject.
The first meal of the day may help boost some people's metabolism, but not everyone's! I'm on a 16 hour Intermittent Fasting Protocol and don't eat until 3-4pm every single day. I am in the best shape of my life and feel GREAT after following this for over a year.
Hate to have to call people out but that is what this community is all about, TRUTHFUL, EVIDENCE BACKED information. Thanks @depth