I just spent an hour talking with a lovely lady that recently started eating low carb. She’s morbidly obese, she has never exercised in her life and she really enjoys her vodka pre mixes. And she’s weak: after three weeks low carb, she complains she has no energy and that this diet doesn’t work for her.
Reality check: if you are obese is because you abused your body for a very long time, a few weeks eating healthy won’t be enough to transform you in a fat burning machine capable of running all day long.
Even an elite athlete needs for weeks to become fat adapted coming from a high carb diet, and it could be a much longer transition for someone so fat like this lovely lady. I like to be brutally honest and say from the beginning that the adaptation process can last as long as twelve weeks, but for some of the benefits of being in ketosis it could take months.
Not only you are turning things completely over for your metabolism from one day to another, but mobilizing all those fatty acids (burning fat) is making a mess of your blood lipid profile, your electrolytes would probably be all messed up if you are not careful and well, all this will most likely make you feel non exactly fine for a while.
So, bottom line: if you are an athlete, switching to a low carb diet requires approximately four weeks of adaptation before being completely fat adapted, but if you are an overweight person this period will be much longer and there is a chance that you won’t feel too great either until it’s done.
After that, it’s all downhill.
It’s possible to minimize the length and inconveniences of this adaptation period, mostly keeping your electrolytes well balanced, and some coaches suggest reducing your carbs a little bit at a time in a period of a few weeks. In my opinion it only keeps the adaptation period longer than it should be, and psychologically could be much easier to ditch the carbs all at once instead of keeping the cravings for several weeks, but at the end of the day, whatever works for you is good.