Let's be honest about it: it's not all smooth sailing.

Reason 1: Social Awkwardness

Keto won't make you popular with friends and family.

By default, the typical Western meal always contains some carbs. It's hard to eat out (or in!) with other people: some kinds of restaurants just won't serve anything you can eat. You'll be a bit of a pain, like a vegan among non-vegans.

Reason 2: Constipation

Much dietary fibre (bran, whole wheat, etc) is carbs. Stop eating that, and something else also stops. I found ways around it but it's been quite unpleasant.

Reason 3: Exclusion of Preferred Tasty Foods

There's a bunch of stuff you want but can no longer eat.

Unfortunately, much of it is precisely the foods that you liked the most. The carb-rich foods you craved made you fat, by elevating your insulin, and the resulting energy depletion made you desire more carbs. Vicious circle.

Reason 4: Difficulty Maintaining Ketosis

Initially, you can't tell whether you even are in ketosis. You must measure it, and the reliable methods (blood test strips) are expensive. And, even when you measure, you need lots of fine tuning and experimentation to achieve more than mild ketosis.

And it gets worse with age, as your hormones change and metabolism slows down.

But watch out for the companion piece—why keto is better than the alternatives