The last taxi I got was an Uber. I was on the way to get a burger at a restaurant. The driver told me that he had started going to the gym recently and was dieting for his wedding that was coming up in two weeks time. I told him that I was a keen gym-goer too and this resulted in him telling me all about his diet. He told me that he was counting calories and I thought to myself "ah yes, this guy is doing it right!" ... he then said he was eating 700 calories a day and doing a 24 hour fast twice per week.
Now I'm not one to preach to strangers, so I didn't argue. However, I did ask why he was only eating 700 calories. His response was that he found a diet plan online. A one-size-fits-all diet. I hope this is already boggling your mind as much as it is mine. For people with different activity levels and different weights this just doesn't make any sense.
He then boggled my mind even further by saying that "low calorie diets paired with fasting activate starvation mode". The temptation to open the door of the vehicle travelling at 50mph and jump out was there, but I resisted. Starvation mode as he was thinking of it does not exist. You can't significantly affect your metabolism until you are below the necessary levels of body fat to sustain life. Victims of the holocaust experienced starvation. Not uneducated folk who hop on the latest dieting trends. You WILL however seriously disrupt hormonal levels which will likely cause the scale to halt due to water retention and increase your appetite making it more and more likely that you snap and binge. As a male you should be trying to consume 1500 calories as a daily minimum unless you're very short. 1200 calories or less on a regular basis can increase the risk of malnutrition, hormonal imbalance issues, gall bladder issues, and loss of lean mass. In other words: you don't (not would you want to) activate this magical starvation mode by fasting or eating ridiculously low numbers of calories. This is what I wanted to tell my Uber driver but didn't, just in case he gave me a 1-star rating. I then thanked him, hopped out the car, and proceeded to order a 700 calorie burger.