The "low-carb flu" is the phenomenon that causes you to experience flu-like symptoms for the first 3-4 days after you cut carbs. It happens for a reason. Protein and fat provide energy, but they're more long-term, where carbs are your body's main source of quick energy; when you abruptly give up carbs, your blood sugar will plummet. Carbs are also your main source of fiber, so cutting them can lead to constipation, nausea, and bloating. Finally, you lose a lot of water weight once you cut carbs, which can be a good thing for starting to lose weight, but if you don't replenish those water stores, you'll become dehydrated and experience headaches and weakness. Though there are good reasons for all of these symptoms in response to carb loss, it's frustrating! How can you lose weight if the only way to feel better is to eat carbs again? The answer: Use this plan from weight loss expert Dr. Kellyann Petrucci to stick to your diet without suffering!
Quiz: Are You Carb Intolerant?