Is skipping meals a bad idea or a secret weight loss weapon? Discover the health benefits of intermittent fasting for weight loss and the best 5 methods.
Intermittent fasting involves periods of entirely or partially abstaining from eating. There are many intermittent fasting routines and methods, with the most common intermittent fasting methods being 16/8, 5:2 and alternate day fasting.
- The 16/8 method: Also called the Leangains protocol, it involves skipping breakfast and restricting your daily eating period to 8 hours, such as 1–9 p.m. Then you fast for 16 hours in between.
- Eat-Stop-Eat: This involves fasting for 24 hours, once or twice a week, for example by not eating from dinner one day until dinner the next day.
- The 5:2 diet: With this method, you consume only 500–600 calories on two nonconsecutive days of the week, but eat normally the other 5 days.
Some studies suggest that intermittent fasting benefits many aspects of our health such as fat loss, improved health, and increased longevity. Advocates claim it is an easier method of weight loss to maintain than traditional, calorie-controlled diets.
An intermittent fasting pattern is based on a set schedule and is not choosing not to eat at random times.
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What Happens To My Body During Intermittent Fasting?
When you fast your body makes changes at the cellular and molecular level. Your body adjusts your hormone levels which makes stored body fat more accessible. Your cells start important repair processes and change the expression of genes.
Here are some changes that occur in your body when you fast:
- Human Growth Hormone (HGH): The levels of growth hormone increase, as much as 5 times. This benefits both fat loss and muscle gain. There is much evidence to support this 1Growth hormone and sex steroid administration in healthy aged women and men: a randomized controlled trial.
- Insulin: Levels of insulin drop dramatically. Studies show that lower insulin levels make stored body fat more accessible.2Intermittent fasting: is there a role in the treatment of diabetes? A review of the literature and guide for primary care physicians.
- Cellular repair: When you fast your cells initiate cellular repair processes. Studies show the body enters autophagy.3The effect of fasting or calorie restriction on autophagy induction: A review of the literature. This means the cells remove old and dysfunctional proteins that have built up.
- Gene expression: Research shows changes take place in the function of genes related to longevity and disease protection.4Practicality of intermittent fasting in humans and its effect on oxidative stress and genes related to aging and metabolism.
Thes changes in hormone levels, cell function and gene expression are responsible for the health benefits of intermittent fasting.
How to succeed with intermittent fasting periods.
Many people have no problem starting intermittent fasting diets due to them taking no time to prepare and having no additional cost. Others find it challenging to start, especially when they are used to eating three meals and snacks every day. Here are some tips for success:
Pick the right intermittent fasting options To Begin.
Start gradually. Choose a set time routine such as the 16:8, or calorie and time based, such as the 5:2. Once this routine is successful you can consider gradually increasing the fasting periods. It is important to note that fasting periods of 36 hours or more should only be done under the supervision of an experienced health care provider.
Keep Well Hydrated While Fasting.
Fasting means not eating. You can and should drink. Drinking plenty of water helps to mitigate dehydration. The action of drinking mimics eating while putting something in your stomach. Drinking helps you physically and psychologically which will help you become successful with your weight loss goals.
Find New Ways To Distract Yourself.
Most weight loss programmes fail due to our snacking habits. Interestingly snacking isn’t a response to hunger, its a filler activity and way to distract ourselves. So you need to find other ways to avoid the snacking. Read books, play games with the family, go for a walk or do puzzles. The activity doesnt matter as long as it distracts you and avoids your thinking of snacking.
Choose Foods full of protein and nutrient rich.
Studies show that keto diets and high protein diets help with satiety.5Does a Higher Protein Diet Promote Satiety and Weight Loss Independent of Carbohydrate Content? An 8-Week Low-Energy Diet (LED) Intervention. That may be why many low-carb clinicians find people following these diets have greater success with fasting.
5 Popular Intermittent Fasting Methods.
When you are ready to try intermittent fasting, you’ll need to figure out the method most likely to be successful for your lifestyle and routines, especially when it comes to social events and family schedules. Here are 5 of the most popular.
12 Hour Fasting.
The rules for this diet are simple. You need to decide on and adhere to the same 12 hour fasting window every day. You eat a calorie contolled diet for 12 hours and then fast for 12 hours.
Research shows that fasting for 10 to 16 hours can cause the body to turn its fat stores into energy6If you don’t eat for 10–16 hours, your body will go to its fat stores for energy, and fatty acids called ketones will be released into the bloodstream. This has been shown to protect memory and learning functionality, says Mattson, as well as slow disease processes in the brain., which releases ketones into the bloodstream. This encourages weight loss.
This is possibly the most successful intermittent fasting routine for those beginning. This is because the fasting window is large enough for your body to release ketones but small enough to stick to! You can plan for most of the fasting to occur during sleep, and it is easy for you to plan to consume the same number of calories each day.
Plan your 12 hour fast to happen during your regular sleep cycle. This means you might choose to fast between 7 p.m. and 7 a.m. This means dinner before 7 pm and breakfast at 7 am. Most of the fast will be spent sleeping.
The Leangains Method – 16 hour fast.
During the Leangains or 16:8 diet, you fast for 16 hours each day. This type of intermittent fast is popular among those building muscle mass and may be helpful if you have already tried the 12 hour fast but did not achieve the benefits you were hoping for.
This fast also enables you to use your sleep period as part of the fasting window. You could, for example, finish your evening meal by 8 pm, skip breakfast the next day and start eating with your lunch at noon.
One research study was conducted with mice placed on a high fat diet. It found that those mice with an 8 hour feeding window were protected from obesity, inflammation, diabetes, and liver disease, even when they ate the same number of calories as the mice allowed to eat whenever they wished.7Time restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high fat diet.
The 5:2 Fasting Plan.
The 5:2 diet is easier than many intermittent fasts. This is due to there not being any days without eating. For five days a week, you eat normally without thinking about restricting calories. On the other two days, you reduce your calories to approximately a quarter of your daily needs. On average that means 500 calories per day for women, and 600 for men.
The 2 fasting days can bed any that you prefer. The only rule is there must be at least one non-fasting day between them. One common method for planning your week is to fast on Mondays and Thursdays, and then eat normally on the other days. On fasting days you can divide your eating into small snacks or 2 larger meals, as long as you don’t exceed your calorie limit.
We should point out that eating normally doesn’t mean you can eat anything. If you binge on junk food, then you probably won’t lose weight, and may even put it on. You should eat a normal healthy diet.
Research studies found that the 5:2 diet helped reduce insulin levels and improved insulin sensitivity among participants.8Effect of Intermittent Fasting Diet on Glucose and Lipid Metabolism and Insulin Resistance in Patients with Impaired Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis.
Alternate Day Fasting.
Alternate day fasting involves fasting every other day. There are 2 common methods that can be used. The first is complete avoidance of food on fasting days, with the second allowing 500 calories on fasting days. On the non fasting days you eat as normal.
One study reported that alternate day fasting is effective for weight loss as well as benefiting heart health in both healthy and overweight adults.9Alternate day fasting for weight loss in normal weight and overweight subjects: a randomized controlled trial. Researchers found that the 32 participants lost an average of 5.2 kg, or just over 11 lb, in the 12 week research period.
Alternate day fasting is considered an extreme form of fasting. It therefore may not be suitable if you are a beginner or if you have certain medical conditions. You should check with your health provider before starting.
the weekly 24 hour fast.
The weekly 24 hour fast is part of a group called Eat-Stop-Eat diets. The eat stop eat method involves eating no food for a period of 24 hours. An example is to choose one day of the week to fast from 9am one day to 9am the next. Or from noon until noon on the following day.
Followers of this diet plan must remember they arfe allowed water, tea, and other calorie free drinks during the fasting period. You then return to your regular eating patterns on other days. This plan is based on reducing your total weekly calorie intake without limiting the specific foods you consume.
A 24-hour fast may not sound difficult but it can actually be extremely challenging. Many people report fatigue, headaches, and irritability as common side effects. However these are reporteds to become less extreme over time as your body adjusts.
Fasting Precautions and Those Who Should Not Fast.
Most people can safely and successfully use fasting and experience few, if any, side effects. There are however some individuals who should avoid fasting, or should only do so under the care and observation of their health professional.
Those Pregnant and breastfeeding. Both significantly increase energy demands of the mother. Fasting could potentially deprive her and the baby of essential calories and nutrients.
Women trying to get pregnant may find that fasting disrupts their menstrual cycle and may lower fertility.
Children have much higher energy demands than adults, due to rapid growth rate. Fasting is therefore not generally considered appropriate or safe for children.
Anyone underweight or malnourished should avoid fasting. Also anyone with a history of eating disorders such as anorexia or bulimia should avoid fasting. Fasting could potentially trigger eating disorder tendencies and place them at risk.
Those taking medications that lower blood sugar, such as insulin, should never attempt fasting on their own due to the significant risks involved. They should only fast under the guidance of an experienced medical professional.
References
- 1Growth hormone and sex steroid administration in healthy aged women and men: a randomized controlled trial.
- 2Intermittent fasting: is there a role in the treatment of diabetes? A review of the literature and guide for primary care physicians.
- 3The effect of fasting or calorie restriction on autophagy induction: A review of the literature.
- 4Practicality of intermittent fasting in humans and its effect on oxidative stress and genes related to aging and metabolism.
- 5Does a Higher Protein Diet Promote Satiety and Weight Loss Independent of Carbohydrate Content? An 8-Week Low-Energy Diet (LED) Intervention.
- 6If you don’t eat for 10–16 hours, your body will go to its fat stores for energy, and fatty acids called ketones will be released into the bloodstream. This has been shown to protect memory and learning functionality, says Mattson, as well as slow disease processes in the brain.
- 7Time restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high fat diet.
- 8Effect of Intermittent Fasting Diet on Glucose and Lipid Metabolism and Insulin Resistance in Patients with Impaired Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis.
- 9Alternate day fasting for weight loss in normal weight and overweight subjects: a randomized controlled trial.