People often struggle with lethargy and muscle-tiredness in the beginning of the LCHF journey. Its because your body has been used to getting easy energy from the high carbs you’ve been feeding it. When you stop the supply of quick energy to your system it may be slow in taking the hint. Instead of immediately finding energy from your fat stores, it waits and waits for you to feed it high carbs again
When it realizes that you’re not going to do so, it finally turns to your fat energy deposits to give you fuel. It’s this particular time that can leave you tired and weak. However, if you stick with it through those initial days, your body will soon learn to get it’s energy from the right places and you’ll have soon have more energy than before.
If you stop eating sugar and starch cold turkey, you may experience more severe side effects as your body adjusts. Common side effects in the first weeks of low carbing include headaches, fatigue, dizziness, heart palpitations, jitters and irritability.
These side effects rapidly subside as your body adapts to your eating lesser carbs and your fat burning then should begin to increase. Side effects can be minimized by drinking more fluids and by temporarily increasing your salt intake a bit more. A good option is to drink broth or soup every few hours. Also drink a few extra glasses of water and put more salt on your other food.
The reason for these side effects are that carbohydrate-rich foods may increase the water retention(storage) in your body. When you stop eating high-carb foods you tend to lose a lot of excess water through your kidneys. This often results in dehydration and a lack/shortage of salt during the first weeks, before the body gets adapted.
Removing/reducing drastically most carbs (sugar and starch) in your diet often results in several pounds lost on the scale within a few days. This is a great motivation for beginners to continue to strive with lchf.