Intermittent fasting and its flexibility

• Intermittent fasts: eating no food or massively cutting back on calorie intake only intermittently;
• Time-restricted feeding: involves consuming calories only for a 4- to 6-hour window each day.
• Periodic fasts, the most extreme, typically last several days or longer. 
• Fasting-mimicking diet, a plant-based diet that involves eating very few calories for several days each month. 

Many religious groups incorporate periods of fasting into their rituals, though the focus there tends to be more spiritual than health-oriented: Muslims fast from dawn until dusk during the month of Ramadan, Christians, Jews, Buddhists, and Hindus who traditionally fast on designated days of the week or calendar year.

• Skipped meals - when you skip over a meal to induce extra time of fasting. 
• Eating windows - this condenses your entire macronutrient intake between a 4 and 7-hour window. The rest of the time you are in a fasting state.
• 24-48 hour cleanse - where you go into extended fasting periods and do not eat for 1-2 days.

The process by which the cell devours itself.

• Non-essential parts like damaged proteins are recycled and invading microorganisms and toxic compounds are removed. 
• Autophagy plays an important role in stopping the aging process, reversing disease, and preventing cancer, but it doesn’t happen all the time. 
• Autophagic processes can be initiated by fasting, protein restriction and carbohydrate restriction.

• It makes your day simpler: fewer meals= less stressing about what you'll eat.
• It helps you live longer: you get the benefits of a longer life without the hassle of starving.
• Still up for debate, but intermittent fasting may reduce the risk of cancer.
• It is much easier than dieting, once you get over the idea that you need to eat all the time.

• Daily Intermittent Fasting: 16–hour fast followed by an 8–hour eating period. 
• Weekly Intermittent Fasting: One of the best ways to get started with it - do it once per week.
• Alternate Day Intermittent Fasting: incorporates longer fasting periods on alternating days throughout the week.

Exercise is like a wonder drug for many health outcomes: reducing blood pressure, reduces the risk of diabetes of heart diseases and slows developing cognitive impairment from Alzheimer's and dementia. 

But as for losing weight, it helps more in weight maintenance than in losing the actual weight.

Exercise alone has a modest contribution to weight loss. But when you alter one component, cutting the number of calories you eat in a day to lose weight, doing more exercise than usual, this sets off a cascade of changes in the body that affect how many calories you use up and, in turn, your bodyweight.

The brain’s response to caloric restriction tends to be to increase cravings for foods that are highly rewarding and reducing our perception of being full. 

Diets frequently fail because they have an endpoint and are not a real lifestyle change. Maintaining a lifestyle that promotes a healthy weight and metabolism is often a lifelong journey. 

The actual food you eat isn’t the main thing that enables you to keep weight off.

Maintaining a weight-reduced state is a lifelong journey and many dietary approaches can work to facilitate weight loss and keep it off.

• The 5:2 Pattern: restrict your calorie intake for two days per week (500 calories per day for women and 600 for men).
• The 6:1 Pattern: similar to the 5:2, but there’s only one day of reduced calorie intake instead of two.
• “Eat Stop Eat”: a 24-hour complete fast, 1–2 times per week.
• The 16:8 Pattern: only consuming food in an eight-hour window and fasting for 16 hours a day, every day of the week.

Longer periods of fasting increase your risk of side effects, such as dehydration, dizziness, and fainting. 

The best way to avoid these side effects is to stick to shorter fasting periods of up to 24 hours — especially when you’re just starting out.