Fasting one day a week for weight loss appears to be an unachievable objective, given how most common diets require daily meal practices or alternatively, how fulfilling it is to eat more calories every hour whenever you feel hungry.
However, there are several things fasting can do to improve your body’s ability to drop a pound a day. The benefits of fasting and how to lose weight once a week will be explained more below.
What Is Fasting?
Intermittent fasting is a type of fasting used to lose weight or, at times, even for health reasons. It has grown in popularity in recent years as more people adopt it.
Intermittent fasting is a method of eating that consists of frequent short-term fasts. These brief fasts allow you to ingest fewer calories. They also aid in the optimization of your body’s hormones associated with weight control.
When you fast, hunger is usually not a major concern, but it can be in the beginning as your body adjusts to not eating for extended periods of time. Taking supplements while fasting is generally permitted as long as they contain no calories1.
Fasting One Day A Week For Weight Loss
Fasting for weight reduction benefits, whether through water fasting or the warrior diet, requires consistency and patience. The amount of fat you lose is heavily influenced by how long and how frequently you fast.
A 24-hour fasts, in which you do not eat for at least 24 hours, can benefit your body and general health in a variety of ways if done correctly. These fasts do not have to be done on a regular basis; even once a week is sufficient to get some of the health benefits2.
In addition to these elements, the quality of the foods you eat thereafter is important. Fasting for 16-20 hours per day allows you to shed roughly 2-3 pounds of body fat every week.
Different Approaches To Intermittent Fasting
- Alternate-day Fasting Period
- This fast requires alternating between days with no dietary restriction and days with one meal that supplies around 25% of your daily calorie needs. For example, fasting is observed on Mondays, Wednesdays, and Fridays, with no food restrictions on the other days3.
- Whole-day Fasting
- 1-2 days a week of complete fasting, or up to 25% of daily calorie needs, with no food restrictions on the remaining days. The 5:2 diet plan, for example, advises no dietary restriction five days per week, followed by a 400-500 calorie diet the remaining two days3.
- Time-restricted Feeding
- Following a daily meal plan with a fasting time frame. For instance, meals are served from 8 a.m. to 3 p.m., with fasting occurring during the remaining hours of the day3.
Different Stages Of Fasting
When you fast, your body goes through the fed-fast cycle, which is defined by changes in your metabolism and hormone levels.
This cycle is not only responsible for the metabolic alterations that occur during intermittent fasting, but it is also attributed with providing some of its health benefits.
- Fed State
- Your body enters the fed state within the first several hours after eating as it digests and absorbs nutrients from meals. During this time, your blood sugar levels rise and you produce more insulin. Insulin is the hormone that transports sugar from the bloodstream to the cells4.
- The amount of insulin released is determined by the composition of your meal, the amount of carbohydrates taken, and your body’s insulin sensitivity5. It is important to note that when food is consumed during a fast, the fed-fast cycle is reset to the fed state.
- Furthermore, the amount and substance of your meal influences how long your body remains in a fed state.
- Early Fasting State
- Your body enters an early fasting state around 3-4 hours after eating, which lasts for about 18 hours. During this stage, your blood sugar and insulin levels begin to fall, prompting your body to begin converting glycogen into glucose (sugar) for energy4.
- By the conclusion of this phase, your body will have depleted its liver glycogen stores and will begin looking for another energy source. This increases lipolysis, the breakdown of triglycerides from fat cells into smaller molecules that can be used as an alternative fuel source6.
- Fasting State
- The fasting period can last anything from 18 hours to two days. Your glycogen stores in the liver have been depleted by this stage, and your body has begun to break down protein and fat stores for energy instead.
- This causes the formation of ketone bodies, which are a sort of substance formed when your body transforms fat into fuel7. This also leads your body to enter ketosis, a metabolic condition in which your body burns fat for energy8.
- Furthermore, forms of intermittent fasting with shorter fasting windows of 12-18 hours per day may not accomplish this state, as ketosis cannot be established with fasts lasting fewer than 24 hours unless you also follow an extremely low-carb diet.
- Long-term Fasting State (Starvation State)
- During prolonged fasting, your body enters the long-term fasting state, which usually happens 48 hours following food intake. This is regarded as a starving state by some.
- Long-term fasting causes insulin levels to fall as levels of beta-hydroxybutyrate (BHB), a kind of ketone body, steadily rise4,9.
- Your kidneys also continue to produce sugar through a process known as gluconeogenesis, which is the primary source of fuel for the brain. At this moment, ketone bodies also supply energy to your brain4,10.
- The breakdown of three important amino acids, branched-chain amino acids (BCAAs), is also reduced to assist conserve muscle tissue in the body4.
Health Benefits Of Fasting Once A Week
- Weight Loss
- Any extended durations of fasting aids in weight loss by decreasing the number of calories consumed. To lose weight and body fat, you must be in a calorie deficit, which means you must be consuming fewer calories than you burn.
- Intermittent fasting can be an effective weight loss strategy. However, the advantages of intermittent fasting extend far beyond weight loss. Although counting calories is not usually required when conducting intermittent fasting, the weight loss is mostly mediated by a reduction in overall calorie intake.
- When calories are matched between groups, studies comparing intermittent fasting and daily calorie restriction indicate no difference in weight loss11.
- Reducing Insulin Resistance
- Fasting for many hours on a regular basis helps reduce insulin resistance, which is helpful for your blood sugar levels. If you have significant insulin resistance, your blood sugar levels will remain high, increasing your chances of developing type 2 diabetes.
- Reduced insulin resistance makes your body more sensitive to insulin (which is a good thing) and allows it to carry glucose from your bloodstream to your cells much more efficiently12.
- Improves Heart Health
- Fasting, particularly alternate-day fasting, has been shown to benefit overall heart health. Heart disease is the leading cause of death worldwide, accounting for over one-third of all fatalities.
- Fasting can lower your “bad” LDL cholesterol and blood triglycerides, lowering your risk of cardiovascular diseases. Such dietary adjustments can also help to lower blood pressure and cholesterol levels, as well as protect against diabetes12.
- Prevents Inflammation
- While acute inflammation is your body’s natural response to fighting off things like infections, chronic inflammation – which lasts far longer – can be harmful and lead to health concerns like heart disease.
- Fasting, including 24-hour fasts, has been demonstrated in studies to aid in the fight against chronic inflammation. This reduces your risk of getting chronic diseases and other health disorders, such as multiple sclerosis12.
- Regulates Hormones
- Hunger and fullness are actually hormones – ghrelin and leptin, respectively – and fasting for longer periods of time can help control these hormones and keep them at appropriate levels.
- Ghrelin regulates your hunger; low amounts of this hormone make you feel more hungry, while high levels make you feel less hungry. Leptin, on the other hand, informs us when we are full, therefore if your leptin levels are high, you will need to eat more food to feel satisfied. Obese people have high leptin levels and low ghrelin or hunger levels12.
- Makes Healthy Eating Simple
- One of the primary advantages of intermittent fasting for many people is its simplicity. Instead of tracking calories, most intermittent fasting regimens just need you to keep track of the time.
- The optimal eating plan for you is one that you can maintain over time. If intermittent fasting helps you stay on a nutritious diet, it will have apparent long-term health and weight maintenance benefits11.
- Other Health Benefits
- Maintaining muscle mass
- Reduce blood pressure
- Boosts brain function
- Boosts immune system
How To Do Fasting Once A Week?
Fasting entirely for one or two days per week, often known as the Eat-Stop-Eat diet, entails not eating for 24 hours at a time. Many people fast from one meal to the next, such as breakfast to lunch. During the fasting time, you can drink water, tea, and other calorie-free beverages.
On non-fasting days, you should resume your normal eating habits. Eating in this manner reduces your total calorie consumption but it does not restrict specific items to consume.
However, it is not recommended to do a 24 hour fast consecutively. A 24-hour fast can be difficult, causing weariness, headaches, and irritation. Many people find that when their bodies acclimate to this new eating pattern, the symptoms become less severe. Before attempting the 24-hour fast, people may benefit from doing a 12-hour or 16-hour fast13.
Going a day without eating is generally safe and can be useful in a variety of ways, including as a strategy for weight loss. But keep in mind that fasting does not help with weight loss any more than other conventional methods and can be more difficult to maintain in the long run.
Fasting for weight loss or especially for health reasons should be done safely and for no longer than necessary. Fasting for an extended period of time deprives your body of necessary nutrients and can lead to a variety of issues.
One thing is certain, when done properly and consistently, fasting can result in weight loss and many other benefits not limited to weight loss alone.
4 Stockman, M. C., Thomas, D., Burke, J., & Apovian, C. M. (2018). Intermittent Fasting: Is the Wait Worth the Weight?. Current obesity reports, 7(2), 172–185. https://doi.org/10.1007/s13679-018-0308-9
5 Yari, Z., Behrouz, V., Zand, H., & Pourvali, K. (2020). New Insight into Diabetes Management: From Glycemic Index to Dietary Insulin Index. Current diabetes reviews, 16(4), 293–300. https://doi.org/10.2174/1573399815666190614122626
6 Edwards M, Mohiuddin SS. Biochemistry, Lipolysis. [Updated 2022 Jul 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560564/
7 Puchalska, P., & Crawford, P. A. (2017). Multi-dimensional Roles of Ketone Bodies in Fuel Metabolism, Signaling, and Therapeutics. Cell metabolism, 25(2), 262–284. https://doi.org/10.1016/j.cmet.2016.12.022
8 Gershuni, V. M., Yan, S. L., & Medici, V. (2018). Nutritional Ketosis for Weight Management and Reversal of Metabolic Syndrome. Current nutrition reports, 7(3), 97–106. https://doi.org/10.1007/s13668-018-0235-0
10 Mergenthaler, P., Lindauer, U., Dienel, G. A., & Meisel, A. (2013). Sugar for the brain: the role of glucose in physiological and pathological brain function. Trends in neurosciences, 36(10), 587–597. https://doi.org/10.1016/j.tins.2013.07.001