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.
The short answer is yes - fasting can indeed help burn more fat. When we fast, our bodies switch to burning stored fat for energy instead of glucose from food. This can lead to weight loss and even improve our insulin sensitivity.
Early fasting reduces amount of abdominal fat
Upon analysis, Ruiz and his team found that all fasting groups, regardless of the time-restricted fasting method, had more weight loss — on average 3-4 kg — compared to the usual treatment group.
The most common fasting window among users (64.9%) is 11-15 hours, with a fat-burn rate ranging from 37 to 42%. A popular method of intermittent fasting is the 14:10 ratio, in which you fast for 14 hours and consume all your meals in a 10-hour window.
Research has shown that there is no difference in body-fat loss between fasted and fed cardio. Fasted cardio may burn more fat during the time of the actual workout but less the rest of the day, whereas non-fasted cardio may burn less fat during the workout but more throughout the day.
After hepatic glycogen stores are depleted, the body uses adipose tissue and protein for energy. The liver has an active role in the metabolism of fats as it is the main oxidizer of triglycerides. In more extreme versions of fasting, where fat sources have been expended, the body breaks down skeletal muscle for energy.
That plan is called the 30-30-30 rule. It's a simple but catchy idea that encourages you to eat 30 grams of protein within 30 minutes of waking up and then get 30 minutes of low-intensity exercise. The 30-30-30 rule now has millions of followers on TikTok.
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.
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.
If you wake up every morning still burning mostly carbs, it's a sign your diet isn't optimized or you may have lost some metabolic flexibility, becoming dependent on sugars for energy.
Digestion – Fasting is a great way to give your digestive system a break from over-eating or binge-eating as digesting large volumes of food can become stressful for the organs involved in digestion; fasting also shrinks the size of your stomach, so fasting more than once in a week isn't too healthy.
Aerobic exercise includes any activity that raises your heart rate such as walking, dancing, running or swimming. This can also include doing housework, gardening and playing with your children. Other types of exercise such as strength training, Pilates and yoga can also help you lose belly fat.
For those aiming to lose belly fat, the 16/8 method is often recommended as the best intermittent fasting window to lose belly fat. By fasting for 16 hours and eating within an 8-hour window, you give your body enough time to burn stored fat while still allowing for a manageable eating period.
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).
While both 12-hour and 16-hour fasting can promote fat burning, it's possible that a 16-hour fast may be more effective. This is because the longer fasting period may lead to a greater depletion of glycogen stores, which can trigger higher levels of fat burning.
One of the signs of ketosis may include “keto flu,” which includes symptoms such as upset stomach, headache and fatigue. Other symptoms of ketosis may include: Bad breath (“keto” breath). Constipation.
Various researchers have reported that fasting may lead to improvements in liver function, potentially indicating a reduction in liver fat accumulation or inflammation. Additionally, total cholesterol levels, which are known to be associated with NAFLD, may also improve during this fasting period.
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.
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. (A midnight snack obviously sabotages this process.) A keto diet keeps you in ketosis for much longer time periods because you avoid carbohydrates, which supply glucose.
When it comes to nutrition advice via social media, trust me, I've heard worse. The 30-30-30 method refers to consuming 30 grams of protein within 30 minutes of waking, followed by 30 minutes of low-intensity exercise. Biologist Gary Brecka describes the diet on TikTok, which now has more than 17 million views.
4-Hour Body Diet: Health Risks
Restricting entire food groups could lead to deficiencies in certain vitamins and other nutrients, including vitamin D and calcium (found in dairy) and B vitamins such as folic acid (found in grains and fruit).
For example, to lose 1 to 2 pounds a week — a rate that experts consider safe — your food consumption should provide 500 to 1,000 calories less than your total weight-maintenance calories. If you need 2,325 calories a day to maintain your current weight, reduce your daily calories to between 1,325 and 1,825.