Since plants can’t run away, they developed chemical defenses against hungry herbivores. One of these is phytic acid. Phytic acid binds to minerals with positive charges and keeps you from absorbing them. That means you won’t benefit from the iron, zinc, and calcium from the grains you eat. The phytic acid will also bind to positively charged nutrients in any other veggies you eat alongside them.
Some people feel better supplementing the already active T3 (sometimes prepared from pig thyroid glands), as it can give a stronger effect than the T4 hormone, but its effect is often harder to control. Swedish healthcare rarely prescribes or offers such T3 treatment, as it often lacks advantages and may pose a risk when doses are high for an extended period of time.
Cons: In our experience, capping your calories low will probably mean a lot of internal strife and stress. Plus, we’re big fans of enjoying food instead of fearing it, and 800 calories doesn’t leave much room for satisfied taste buds. Lastly, if you’re currently eating double to triple this amount of food, dropping to a daily caloric intake this low can tank your metabolism and actually slow weight loss more than switching to one of these other diets might. (Curious? Here’s why starving yourself won’t help you lose weight.)
Sleep enough – for most people at least seven hours per night on average – and keep stress under control. Sleep deprivation and stress hormones raise blood sugar levels, slowing ketosis and weight loss a bit. Plus they might make it harder to stick to a keto diet, and resist temptations. So while handling sleep and stress will not get you into ketosis on it’s own, it’s still worth thinking about.