Weight loss is very stressful on the body. People can experience a wide variety of withdrawal and detox symptoms during the weight-loss phase of Bright Line Eating. These range from general tiredness to flu-like symptoms, and sometimes people even experience hives and shakiness. The withdrawal symptoms resolve within a few days, but the detox can last well beyond that. The detox is very real and the science behind it is quite simple. Fat cells are the storage facilities of the body. Not only do they store fat, but as the landfills of the body, fat cells also store toxins of all sorts, sometimes for years. When the body loses weight, it does not eliminate fat cells—rather, the fat cells shrink. While the stored fat in those cells is burned as fuel (fat isn’t your body’s preferred fuel source, which is another reason you can be tired from weight loss), the toxins that were stored in those fat cells are dumped into the bloodstream.
Drinking water to help flush those toxins and resting both help with the symptoms. Science shows that eating broccoli can help, too.
It’s really hard to say how long your detox symptoms will last. People’s bodies differ tremendously. For the vast majority of people, it clears up quickly (within a couple of weeks or even a couple of days—this would be the case if the issue were more withdrawal than detox). For Susan, it took much longer. Hypothyroidism was in the mix, and she felt pretty awful for the first six months. That’s highly unusual. For almost everyone, all tiredness and related symptoms of fatigue, detox, and withdrawal are fully absent by three months.
Note that in Susan’s book Bright Line Eating: The Science of Living Happy, Thin, and Free, there is more on fatigue and rest beginning on page 193.