Intermittent fasting can have unpleasant side effects. They could include hunger, fatigue, insomnia, irritability, decreased concentration, nausea, constipation and headaches. Most side effects go away within a month.
Fasting may also lead to an increase in the stress hormone, cortisol, which may lead to even more food cravings. Overeating and binge eating are two common side effects of intermittent fasting. Intermittent fasting is sometimes associated with dehydration because when you do not eat, sometimes you forget to drink.
The benefits of a 16-hour fasting schedule are the same as a 12-hour fasting. They include weight loss, aid in the cellular repair process, improved sleep, improved digestion, increased mental health and clarity, and reduced insulin resistance.
As it stands now, the current evidence supports intermittent fasting as a weight loss method for up to 12 months. Some people are also probably not right for intermittent fasting. It's not recommended for anyone who is pregnant, has diabetes or is under 18.
Longer periods without food, such as 24-, 36-, 48- and 72-hour fasting periods, are not necessarily better for you, and may be dangerous. Going too long without eating might actually encourage your body to start storing more fat in response to starvation.
Intermittent fasting is safe for many people, but it's not for everyone. Skipping meals may not be the best way to manage your weight if you're pregnant or breast-feeding. If you have kidney stones, gastroesophageal reflux, diabetes or other medical problems, talk with your doctor before starting intermittent fasting.
If you're not already used to skipping meals or not eating for an extended period of time, the hunger and fatigue that can occur when starting IF can be difficult to handle. Other side effects can include insomnia, irritability, headaches, and nausea.
The 4-4-12 method has a shorter fasting window—12 hours—but eliminates snacking between meals. The goal here is to fast for at least four hours between breakfast and lunch, four hours between lunch and dinner, and at least 12 hours between dinner and breakfast the next day.
The truth about lemon water and intermittent fasting
Long story short - the answer to the question “Does lemon water break a fast?” is no, lemon water does not break a fast. Lemon water contains almost no calories and zero sugars, it doesn't raise insulin levels, which means it will not break your fast (1).
In the case of Intermittent fasting, skipping your dinner is better and easier. You can have your dinner either early or have a heavy snack and can begin your fasting. Research suggests that fasting in the evening and overnight, then eating early in the morning is the better way to follow this diet to lose weight.
For some, fasting may cause problems. For example, studies have found that people who regularly fast more than 16 or 18 hours a day have a higher risk of gallstones. They're also more likely to need surgery to remove the gallbladder.
Additionally, it will take your body a while to get used to this new eating schedule. So don't expect results right away. You may need to wait between 2 and 4 weeks to see or feel any results.
Fast for 12 hours a day
According to some researchers, fasting for 10–16 hours can cause the body to turn its fat stores into energy, which releases ketones into the bloodstream. This should encourage weight loss. This type of intermittent fasting plan may be a good option for beginners.
Make your first meal of the day all healthy protein (chicken, fish, meat, eggs) with no carbohydrates and your body will continue to burn body fat as if you have not eaten anything at all. 2 hours after your protein meal, have a light snack or two to hold you over for dinner.
Eat a normal diet five days a week and fast two days per week. Eat normally but only within an eight-hour window each day. For example, skip breakfast, but eat lunch around 11 a.m. and dinner by 7 p.m.
Alternate-Day Fasting
This is a popular approach for weight loss. In fact, research found that, in overweight adults, alternate-day fasting significantly reduced body mass index, weight, fat mass, and total cholesterol.
Studies have suggested that intermittent fasting may reduce levels of reproductive hormones in females, leading to potential problems with fertility.
After the first week of intermittent fasting, you'll probably notice less bloating and a tighter, slimmer look and feel to your midsection. Some people will enjoy some weight loss by week two, but don't be discouraged if your weight scale hasn't budged. Continue for another 4-6 weeks, and you should see changes.
This is how much weight you can lose with intermittent fasting. In doing the fast correctly and ensuring that it is aligning with your mind, body and soul–you can expect a good weight loss of anywhere between 2 to 6 kgs a month with excellent inch loss and increase in energy levels and brain function.
When you fast for shorter durations, your body doesn't have enough time to go into ketosis. This means it won't burn stored fat, and there won't be significant weight loss. As one study concluded, a fasting window of 18-19 hours is more effective in terms of weight loss than those between 12-17 hours [11].