Intermittent Fasting
Intermittent fasting is a pattern of eating based on time limits. For a set time of hours or days, you eat a typical diet. At the end of the set time, you switch to very few or no calories, called fasting.
The idea is that intermittent fasting causes the body’s cells to change how they work. Timed eating may push cells to focus on repair, energy use and balancing body-wide functions.
Fasting also affects metabolic processes in the body that may work to decrease inflammation, as well as improve blood sugar regulation and physical stress response. Some research shows this may improve conditions associated with inflammation like arthritis, asthma and multiple sclerosis.
Research shows that intermittent fasting may improve some signs of health in the short term. These include:
- Blood sugar.
- Weight.
- Blood cholesterol.
- Blood pressure.
- Chronic inflammation.
scientists think intermittent fasting may help:
- Boost gut health.
- Enhance brain function and lower your risk of neurological disorders.
- Lower inflammation and joint pain.
- Prevent the progression of Type 2 diabetes by improving how you respond to insulin.
- Reduce your risk of heart disease.
But the long-term health effects of intermittent fasting aren’t clear. And some studies find just limiting calories in general may have the same benefit as intermittent fasting.
Burning Fat
Not eating for an extended period can place the body in short-term ketosis, a metabolic state where the body burns fat for energy instead of glucose.
Ketosis occurs when glucose (the preferred energy source) is depleted, and stored fat is used for fuel.
About 16 hours of fasting may be enough for some people to start producing ketones or enter ketosis.
Calorie Reduction
The main reason that intermittent fasting works for weight loss is that it helps you eat fewer calories.
All the different protocols involve skipping meals during the fasting periods.
Unless you compensate by eating much more during the eating periods, you’ll consume fewer calories.
Hormonal Shifts That Support Fat Loss
Intermittent fasting may help you lose weight but can also affect your hormones.
That’s because body fat is the body’s way of storing energy (calories). When you don’t eat anything, your body makes changes to make stored energy more accessible.
Examples include changes in nervous system activity, as well as significant changes in the levels of several crucial hormones, including
- Insulin: Insulin levels increase when you eat, and when you fast, they decrease dramatically. Lower levels of insulin facilitate fat burning.
- Norepinephrine (noradrenaline):
Your nervous system sends norepinephrine to your fat cells, making them break down body fat into free fatty acids that can be burned for energy.
Short-term fasting may increase fat burning. Research shows that alternate-day fasting and whole-day fasting can reduce body weight and body fat
Still, more research is needed to investigate the long-term effects.
Another hormone that’s altered during a fast is human growth hormone (HGH). Previously, researchers believed HGH helped burn fat faster, but new research shows it may signal the brain to conserve energy, potentially making it harder to lose weight .
By activating a small population of agouti-related protein (AgRP) neurons, HGH may indirectly increase appetite and diminish energy metabolism
Note : The key to achieving weight loss with intermittent fasting is not to overeat during your eating windows. As with any weight loss plan, eating fewer calories than you expend remains the basis for losing weight.
Intermittent fasting can have unpleasant side effects, like hunger, fatigue, insomnia, irritability, decreased concentration, nausea, constipation and headaches. Most side effects go away within a month.
Intermittent fasting also may cause people to feel very tired and dizzy. It can affect diabetes management and cause headaches or mood swings. Intermittent fasting also may cause constipation and affect the menstrual cycle.
Intermittent fasting can be dangerous if taken too far. A technique called dry fasting restricts food and fluid intake. This can result in severe dehydration and pose serious health concerns. Malnutrition can occur if the caloric restriction is too severe, such as averaging fewer than 1,200 calories per day long term.
Researchers don’t know if different fasting cycles have the same benefits. Some evidence suggests that a 16-hour fasting, 8-hour eating cycle may raise heart disease risk compared with other time-restricted eating cycles.
Little long-term research has been conducted on intermittent fasting to examine how it affects people over time. As a result, long-term health benefits or risks are unknown.
Only eating during a short window often means skipping breakfast or dinner. If those meals are important parts of your social life, then intermittent fasting may not work for you.
While intermittent fasting is safe for many people, it may not be a healthy pattern for people who:
- Have an eating disorder.
- Are pregnant or breastfeeding.
- Are at high risk of bone loss and falls.
- Athletes may find it difficult to fuel and refuel appropriately for an active lifestyle
If you’re thinking about intermittent fasting, talk to a healthcare professional about the pluses and minuses. Other eating patterns might work as well or better depending on your health goal
1- It’s easy to follow
Because you don’t have to count calories every day, it’s a simplified plan. That can make sticking to the diet easier, which is what really matters at the end of the day.
2- It’s customizable
You can decide which days you fast and what foods you eat. There’s no specific guidance telling you to eat foods you don’t like or can’t get easily.
1- You may overeat on non-fasting days
One of the biggest challenges is not consuming too many calories on non-fasting days. The hunger from fasting can carry over into the next day
2- It can lead to nutritional deficiencies
If you’re not paying close attention to what you’re eating, you could miss out on important nutrients. For example, there’s little room in the diet for healthy fats on fasting days. So, you need to make up for that on non-fasting days. Salmon, nuts and seeds are good sources of healthy fats.
A multivitamin can also help replace missing vitamins and minerals. But they may cause nausea if you don’t take them with enough food. When possible, it’s best to get the nutrients you need from your foods
3-There’s no guide for what to eat
lack of guidance on what to eat can make it easy to eat the wrong foods.
Consuming less nutritious and inflammation-triggering foods can wipe out the benefits of the 5:2 diet and your overall success. It is recommended avoiding these foods, which include:
- Chips and other unhealthy snacks.
- Commercial baked goods.
- Fast food and deep-fried foods.
- Soda and other sugar-sweetened beverages.
- Ultra-processed foods.
4- You may not feel great on fasting days
In addition to being hungry, people on the 5:2 diet report a range of symptoms on fasting days, such as:
- Fatigue.
- Headaches.
- Irritability.
- Poor concentration.
- Lightheadedness or dizziness.
Easing into the diet slowly can also help. Start by limiting to 900 to 1,000 calories on fasting days to ease in. Then, cut back in increments of 100 to 200 calories until you reach your goal of 500 to 600 calories.
References
intermittent fasting (mayoclinic) (https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/intermittent-fasting/faq-20441303)
Can intermittent fasting help with weight loss? (Harvard Health Publishing) ( https://www.health.harvard.edu/staying-healthy/can-intermittent-fasting-help-with-weight-loss?)
How Intermittent Fasting Can Help You Lose Weight(Healthline) (https://www.healthline.com/nutrition/intermittent-fasting-and-weight-loss?)
Is intermittent fasting a helpful practice or health risk? (mayoclinic) (https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-is-intermittent-fasting-a-helpful-practice-or-health-risk/)
Is intermittent fasting good for weight loss? (mayoclinic) (https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-is-intermittent-fasting-good-for-weight-loss/)
What To Know About the 5:2 Diet (clevelandclinic) (https://health.clevelandclinic.org/5-2-diet)
Related Topics
Other Specialities
Fasting
Fasting refers to abstaining from food and drink for a certain period of time, usually in line with religious beliefs. Fasting, practiced by Muslims during Ramadan, covers a period from sunrise to sunset. Some of the benefits of fasting can include resting the digestive system, weight control and regulating metabolism.
Book your appointment TODAY!
Search on the closest Doctor to your location and book based on specialty. EARN 10 POINTS more with CuraPOINT.
BOOK