Intermittent fasting (IF) has become an increasingly popular diet and eating pattern. It involves cycling between periods of fasting and eating, with various schedules such as 16:8 (fasting for 16 hours and restricting food intake to an 8-hour window) or 5:2 (consuming only 500-600 calories on two days per week).
Despite the benefits of intermittent fasting for weight loss, metabolic health, and longevity, several myths and misconceptions persist.
Common myths about IF include that it forces your body into starvation mode, slows your metabolism, causes muscle loss, is an unsustainable fad diet, is bad for women, leads to overeating, disrupts your social life, and causes low energy.
This article debunks some of the most prevalent myths surrounding intermittent fasting, providing research and evidence on the realities of this eating pattern.
The truth is that with some planning and adjustment, intermittent fasting can be safe, sustainable, and beneficial for many people.
Myth 1: Intermittent Fasting Forces Your Body into Starvation Mode
Starvation mode is a metabolic state the body enters when deprived of adequate calories and nutrition for a prolonged period. In starvation mode, the body slows down its metabolic rate and holds on to fat stores to conserve energy. This is because the body thinks food is scarce and needs energy preservation.
However, research shows intermittent fasting does not cause the body to enter starvation. This is because it involves cycling between periods of fasting and eating, unlike prolonged starvation or calorie restriction.
Studies show intermittent fasting can boost metabolism by 3-14% after 3-24 weeks of practice. This is the opposite effect of starvation mode. Researchers believe metabolism increases because of the body’s adaptive response to fasting periods.
Intermittent fasting has also been found to offer many other health benefits:
- Promotes weight and body fat loss. By restricting calories and meal frequency, intermittent fasting creates a calorie deficit needed for weight loss. Studies show it is as effective as traditional calorie restriction.
- Improves insulin sensitivity and lowers risk of type 2 diabetes. Fasting gives the pancreas a break from producing insulin, which can improve insulin sensitivity over time.
- May reduce inflammation. Studies link intermittent fasting with lower markers of inflammation and reduced oxidative stress.
- Improves cardiovascular health. Intermittent fasting has been shown to improve blood pressure, cholesterol levels, blood triglycerides, and fasting blood sugar.
- Helps prevent neurological disorders. Animal studies suggest intermittent fasting may protect brain neurons and improve cognitive function.
So, in summary, research does not support the myth that intermittent fasting triggers a starvation response. Cycling fasting and eating periods provides metabolic benefits that support weight loss and overall health.
Myth 2: Intermittent Fasting Slows Your Metabolism
Metabolism refers to all the chemical processes in your body that convert food and drinks into energy to power your body’s functions. Many factors influence your metabolic rate, including your age, gender, activity level, and body composition.
Some people believe that restricting calories or extending periods without food, as with intermittent fasting, will slow down metabolism as the body tries to conserve energy. However, research has not shown any meaningful metabolic slowdown from intermittent fasting.
In one study, researchers compared the effects of intermittent fasting versus daily calorie restriction on metabolic rate. They found intermittent fasting over 22 days did not slow down metabolism more than standard daily calorie reduction. Other studies have found metabolic rates remain stable even after several months of intermittent fasting.
Some research indicates intermittent fasting may slightly boost your metabolism. Studies show intermittent fasting can increase levels of the hormone norepinephrine, which triggers the breakdown of fat for energy. Intermittent fasting may also boost metabolism slightly by preserving muscle mass. Because muscle tissue burns more calories than fat, having more muscle raises your resting metabolic rate.
Studies do not support the myth that intermittent fasting inherently slows your metabolic rate. As long as you maintain healthy eating habits during your eating periods, intermittent fasting is unlikely to cause any metabolic slowdown compared to standard calorie restriction.
Myth 3: Intermittent Fasting Causes Muscle Loss
One common myth surrounding intermittent fasting is that it leads to muscle loss. This belief comes from the fact that fasting means consuming fewer calories overall, which could lead to muscle breakdown if protein intake is insufficient.
Intermittent fasting does not cause muscle loss if protein intake is adequate. During fasting periods, the body first breaks down glycogen stores. Muscle protein breakdown is minimized if you consume enough protein on feeding days.
To prevent muscle loss while intermittent fasting, focus on:
- Consuming enough protein – 0.7 to 1 gram per pound of body weight is recommended on feeding days.
- Doing resistance training – Lifting weights triggers muscle protein synthesis, which offsets any increased breakdown.
- Eating high protein meals when you break your fast – Getting 30-40g of protein is ideal.
- Following a reasonable fasting schedule – Avoid extreme forms of fasting.
With proper protein intake and strength training, intermittent fasting can help retain or build muscle. You don’t need to worry about losing hard-earned muscle mass just because you’re fasting.
Myth 4: Intermittent Fasting Is an Unsustainable Fad Diet
Although intermittent fasting has become popular recently, it has a long history of traditional and religious practice. Various forms of fasting have been used for health purposes across cultures for thousands of years.
Experts indicate that intermittent fasting is safe, effective, and sustainable for most people when done properly. Studies show it can be maintained both short-term and long-term without adverse effects.
Some tips for sticking with intermittent fasting in a healthy, sustainable way include:
- Start slowly and ease into your fasting protocol. Begin with 12-14 hours of nighttime fasting and build up gradually to longer fasts.
- During fasting periods, stay hydrated by drinking water, herbal tea, coffee, and other non-caloric beverages. Avoid sweetened drinks.
- Listen to your body and be flexible. Modify or stop fasting if you feel unwell.
- Choose a fasting schedule that works with your lifestyle. Some fast daily for 16-20 hours; others fast 1-2 days weekly.
- Focus on nutritious whole foods during eating windows. Don’t overeat or indulge.
- Consider supplements if medically advised. Electrolytes, multivitamins or protein powders can help during fasting.
- Note feelings of hunger come in waves. Distract yourself, and the urge to eat will usually pass.
- Find social support. Having family or friends doing intermittent fasting, too, can help you stay motivated.
Overall, research does not support the myth that intermittent fasting is just another fad diet. With some simple strategies, it can be done safely and effectively in a sustainable, lifelong way.
Myth 5: Intermittent Fasting Is Bad for Women
Some claim that intermittent fasting can disrupt hormones like estrogen, progesterone, and cortisol in women. This leads to concerns that intermittent fasting may have negative effects on female fertility, menstruation, and menopause.
Intermittent fasting has no negative effects on female hormones. It does not impact fertility or menstrual cycle length in women with normal ovulation, and there is no evidence that it increases cortisol levels.
Intermittent fasting may provide unique benefits for women. Studies show it can help reduce inflammation, improve insulin sensitivity, and stabilize blood sugar levels. This may help with conditions like PCOS that commonly affect women.
Here are some tips for women looking to practice intermittent fasting safely:
- Drink plenty of water and herbal teas during the fasting period. Staying hydrated helps stabilize blood sugar.
- Consider shorter fasting periods like 12-14 hours. Extended fasts beyond 16 hours may be more difficult for some women.
- Listen to your body. Stop fasting if you experience any severe side effects like hormonal imbalances or loss of menstruation.
- Eat enough calories during your eating window, especially getting adequate healthy fats. This supports hormone balance.
- Reduce activity on fasting days if feeling low energy. Focus on restorative yoga, walking, etc.
Overall, the research indicates intermittent fasting performed within reason can be safe and beneficial for women. Pay attention to your body, stick to shorter fasts, and focus on eating nourishing foods in your eating window.
Myth 6: Intermittent Fasting Causes Overeating
One common concern about intermittent fasting is that it can lead to overeating during the eating window due to extreme hunger. There is some truth to this – intermittent fasting does cause fluctuations in the hunger hormone ghrelin.
However, research shows mixed effects on appetite and fullness. Some studies show increased appetite and lower fullness during fasting periods. But others show no increase in appetite and stable levels of satiety hormones. Our bodies seem able to adapt to fasting with appropriate hunger signals.
Tips to manage hunger while fasting:
- Drink plenty of water, coffee, and other non-caloric fluids.
- Distract yourself with work or hobbies during fasting hours.
- Eat high-volume, low-calorie foods like veggies and protein.
- Make sure to eat balanced, nutritious meals during the eating window.
- Consider starting with 12-14 hour fasts and building up.
The bottom line is that intermittent fasting takes some adjustment but should not cause out-of-control hunger and overeating with a little planning. Be smart about food choices and listen to your body’s signals during both fasting and feeding windows. Over time, intermittent fasting seems to improve dietary control for most people.
Myth 7: Intermittent Fasting Disrupts Your Social Life
Many people starting intermittent fasting worry that it will disrupt their social life and cause them to miss out on going to restaurants, parties, and other social events with food and drinks.
However, intermittent fasting does not have to get in the way of having an active social life. Here are some tips:
- Plan fasts around events – Schedule your fasting periods on days you don’t have social commitments. Break your fast for special social occasions.
- Eat before/after – If an event falls during your fasting period, eat a meal before you go so you aren’t tempted. Or join in but wait to eat until after.
- Focus on company, not food – Remind yourself that you are there for the company and conversation, not the food or drinks.
- Bring your own snacks – Offer to be the designated snack bringer and bring low-calorie options you can eat while fasting.
- Avoid peer pressure – Decline food politely rather than feeling pressured to indulge. True friends will understand.
With some planning and willpower, intermittent fasting and an active social life can thrive together. Fasting for health doesn’t mean sacrificing relationships.
Myth 8: Intermittent Fasting Causes Low Energy
One common concern about intermittent fasting is that it can lead to low energy levels, fatigue, and poor concentration due to low blood sugar. However, this is largely a misconception.
During fasting periods, your body first breaks down glycogen stores for quick energy. Glycogen stores are limited and get depleted within 24 hours. After this, your body switches to burning primarily fat for energy. This metabolic switch from burning glucose to burning fat and ketones is known as ketosis.
Fat provides a very efficient, long-lasting and stable source of energy for the body and brain. In fact, once adapted to fasting and fat-burning, most people report feeling sustained energy, mental clarity and focus throughout the day, even during longer 20+ hour fasting periods.
Here are some tips to help maintain energy levels and avoid low blood sugar symptoms while intermittent fasting:
- During your eating window, eat low-glycemic, high-fibre, and high-protein foods. This helps regulate blood sugar. Good options include vegetables, nuts, seeds, eggs, fish, poultry, and lean meats.
- Stay hydrated by drinking water, herbal tea, or black coffee during fasting periods. Dehydration can mimic hypoglycemia.
- Include healthy fats like olive oil, avocado and coconut oil in your meals. Fat provides steady energy and helps you feel satiated longer.
- Avoid added sugars and refined carbohydrates. The blood sugar crashes can leave you feeling tired and sluggish.
- Manage stress. High cortisol levels can deplete blood sugar.
- Move your body. Light exercise can help lower blood sugar and boost energy.
- Get enough high-quality sleep. Fatigue leads to lower energy.
By fueling your body optimally during eating periods and adopting lifestyle habits that stabilize blood sugar, intermittent fasting does not have to lead to low energy. With a little practice, you can learn to reap all the health benefits of fasting while still feeling energized and productive during your day.
The Bottom Line
Intermittent fasting has become an increasingly popular diet and health trend, but there are still many myths and misconceptions about how it works and its effects on the body. By examining some of the most persistent myths about intermittent fasting, we can debunk these false claims with current scientific knowledge and research.
The evidence clearly shows that intermittent fasting can be a safe, effective lifestyle when practiced mindfully. If you have been considering trying intermittent fasting, hopefully this article has debunked some of the common myths holding you back