Intermittent Fasting Can Lead to Muscle Loss, But It Doesn't Have to – Here's Why. Protein and exercise are key to a healthy weight loss journey. Editor's Note: This article has been updated from an earlier version in August 2023. During any weight loss journey, it's common to lose a bit of muscle mass along with fat.
Fat usually comes off first and you can also loose fat and muscle at the same time. If someone has a healthy amount of fat they should not loose muscle too quickly when calorie restricting, but someone starving with little fat would loose ample amounts of muscle.
Fasting is a powerful tool for targeting and reducing belly fat. It works by shifting your body's metabolism from burning sugar to burning fat as its primary source of energy. This metabolic shift is what leads to fat loss, particularly in the abdominal area.
When you fast, your body has to find an alternate source of energy since it's not getting energy from food. The body turns to stored fat to provide energy during the fasting periods, which causes the body to burn fat and leads to weight loss.
What will happen? The muscle loss will be much faster with a caloric deficit and you will lose more muscle than fat. Over time, you will also lose muscle mass and end up with less lean muscle, which is not good for your health and metabolism.
“Strength training is key to building and maintaining muscle. Aim for about 30 minutes of strength-training exercises twice a week,” says Kate. This can include lunges, squats, lifting weights, planks or crunches.
What is the most effective fasting time window? Fat burning typically begins after approximately 12 hours of fasting and escalates between 16 and 24 hours of fasting.
Yes, your body will burn fat before it starts breaking down significant amounts of muscle.
Our data shows 20.7% of users opt for a 16-hour fast or more with a fat-burn rate of 42-46%. The 16:8 fasting ratio often involves skipping breakfast and not eating your first meal until midday.
While most people would think that all fat tissue is the same, in fact, the location makes a big difference. During fasting, fat tissue provides energy to the rest of the body by releasing fatty acid molecules. However, the researchers found visceral fat became resistant to this release of fatty acids during fasting.
The best time to incorporate exercise while fasting is early in the day, to match the body's natural circadian rhythm; Unless you're participating in a heavy weight session or endurance cardio, you can benefit hormonally from fasting after your workout, too (for two to three hours).
You may have difficulty losing weight with intermittent fasting if you're eating too many calories, too few calories, or don't have a balanced diet.
Your body fat percentage isn't budging.
If you're losing weight but your body fat percentage is staying the same, it's probably a sign you're losing muscle. "Your body won't shape the way you want. You'll notice shrinking circumferences, but the pinch-able fat is the same," says Dr. Nadolsky.
The idea behind intermittent fasting is that by restricting food, our bodies will more quickly and efficiently tap our fat stores for energy. While glucose from carbohydrates is our most direct fuel source, we burn fat for energy when glucose isn't available. This happens even more during times of food deprivation.
Intermittent fasting can trigger ketosis, but only if you fast for at least 12 hours and potentially up to 18. It's also not the only way to stimulate ketosis — following a low-carb eating routine or extended periods of intense exercise can also trigger this fat-burning metabolic phase.
Fasting for 16 hours a day, leaving an 8-hour eating window, is called the 16:8 method or the Leangains diet. Some experts may recommend females fast for 14 hours and slowly build their way up to 16 hours, while males can start fasting for 16 hours straight away.
FAQs. Does fasting still count when you're sleeping? Fasting is the practice of abstaining from food, so it doesn't matter what you're doing as long as you're not eating. You can still benefit from fasting even if the majority of your fasting period is while you're asleep.
Keto is short for ketosis, the metabolic process that kicks in when your body runs out of glucose (its preferred energy source) and starts burning stored fat. Your body may go into ketosis after just 12 hours of not eating, which many people do overnight before they "break fast" with a morning meal.
Fasting can cause muscle loss, but it's normally well after 24 hours. And that's not something commonly done by those practising intermittent fasting. The process in which we "lose" muscle occurs when, in order to maintain blood glucose, our amino acids must then be converted into glucose (called de novo glucogenesis).
No, creatine does not break a fast. Creatine contains no calories and does not invoke an insulin response. Keep in mind though, this is only if you consume creatine on its own, such as creatine monohydrate powder dissolved in water, unsweet coffee, or unsweet tea.