How Many Carbs Should I Eat While Intermittent Fasting?:— Intermittent fasting carb requirements is probably a question you’ve asked before. If you are on the ketogenic diet or trying to lose weight doing intermittent fasting, it’s a must to understand how many carbohydrates you can eat while intermittent fasting.
It’s not always clear how many carbs one should eat while intermittent fasting, especially when using a low carb diet. I compiled some information from various sources on the topic.
What Is Intermittent Fasting (IF)?
Intermittent fasting (IF) is an eating pattern that cycles between periods of fasting and eating.
It doesn’t specify which foods you should eat but rather when you should eat them.
In this respect, it’s not a diet in the conventional sense but more accurately described as an eating pattern.
Common intermittent fasting methods involve daily 16-hour fasts or fasting for 24 hours, twice per week.
Fasting has been a practice throughout human evolution. Ancient hunter-gatherers didn’t have supermarkets, refrigerators or food available year-round. Sometimes they couldn’t find anything to eat.
As a result, humans evolved to be able to function without food for extended periods of time.
In fact, fasting from time to time is more natural than always eating 3–4 (or more) meals per day.
Fasting is also often done for religious or spiritual reasons, including in Islam, Christianity, Judaism and Buddhism.
Different types of fasting
While there are many different forms of fasting, people can choose the method that best suits their needs. Some examples of fasting methods are below.
Complete alternate day fasting
This form of fasting involves alternating fasting days with eating days.
During fasting days, people will tend to avoid consuming food and drink that contains energy or calories.
On eating days, they can consume as much calorie-containing food and beverages as necessary.
Modified fasting
This form of fasting involves alternate days of fasting and eating.
On fasting days, people will typically only consume 20–25% of their calorie needs and consume as many calories as they need on eating days.
A popular version of this form of fasting is the 5:2 diet.
People who follow this diet fast for two nonconsecutive days per week.
Time-restricted eating
Intermittent fasting involves restricting the window in which a person can eat to a few hours per day.
For example, some people may have an eating window of between 12–6 p.m. and fast outside of these hours.
Ramadan fasting
Ramadan is a holy month that people following Islam celebrate. During Ramadan, individuals may fast between dawn and sunset.
A common dietary practice of Ramadan fasting is to consume a large meal after sunset and then a lighter meal before dawn.
Other religious fasts
People who follow other religions may take part in specific fasts.
For example, people following the Church of Jesus Christ of Latter-day Saints may not consume food or drink for extended periods.
Others who follow the Seventh-day Adventist Church may have their last meal in the afternoon and fast until the next morning.
Understanding Low-Carb Intermittent Fasting
What is intermittent fasting with a low carb diet? Low carb intermittent fasting is any union of two weight loss methods- intermittent fasting and a low carb meal plan, such as the keto diet. Adhering to one enhances the other and vice versa. Intermittent fasting with a low carb diet aims to lower blood sugar and burn fat by reducing carbs (calories) and inducing ketosis. Many health-conscious people use a combination of low-carb keto diet and intermittent fasting to drop weight and control other health conditions.
Intermittent Fasting Vs Low-Carb Diets
We always chant 1+1=2, but how did we arrive at 2? You first have to understand the building blocks, i.e., what 1 is. Using the same analogy to better understand the low carb intermittent fasting meal plan, it is important to know the role of individual meal plans.
Intermittent Fasting (IF)
Unlike most diets, intermittent fasting focuses on when you eat and not what you eat . There are several types of intermittent fasting, for example, 16/8 fasting and 5:2 approach. The bottom line on how to do intermittent fasting is that you will have to eat only within a specific time window regardless of the approach taken. For instance, eat during the day and fast during the day, eat regularly five days a week, limit yourself to one 500–600 calorie meal on the other two days, or eat for eight hours and fast for 16. Besides eating and fasting, sleep also plays an important role in the IF plan since it prevents you from eating when you are not supposed to, and according to the New York Times, it is considered a fasting phase.
Benefits Of Intermittent Fasting
IF might be a realistic, sustainable, safe, and incredibly effective weight loss and diabetes prevention method if you follow the fasting and eating periods of the plan as dictated. Its benefits include:
- Weight Loss
Although weight loss is usually associated with reduced calories, you do not have to worry too much about the number of calories you consume with intermittent fasting. When cells do not use all the carbs that are broken down into sugar for energy, the excess is stored in the fat cells using insulin. When you do not snack during the fasting phase, insulin levels decrease, and the fat cells can then release their stored sugar to be used as energy. Simply put, the body uses your fat reserves for energy during the fasting phase. Therefore, weight loss in IF occurs when insulin levels go down far enough and for long enough that you burn off extra fat.
- Reduces Insulin Resistance
A review of literature published in the Clinical Diabetes and Endocrinology journal concluded that IF minimizes insulin resistance. This means that regular periods of eating and fasting may help protect you against type 2 diabetes, a disorder primarily caused by insulin resistance, specifically in adipose tissue, skeletal muscle, and liver. The research also established that IF effectively decreases weight, leptin levels, fasting glucose, fasting insulin and increases adiponectin levels. Intermittent fasting may help burn fat in the liver and reverse insulin resistance and type 2 diabetes, but should only be done by diabetic patients while under medical supervision.
- Inflammation
WebMD defines inflammation as a process by which the body’s immune system protects you from outside invaders. This process can sometimes malfunction where white blood cells trigger inflammation when there are no invaders to fight off. This may be involved in many chronic diseases such as cancer, heart disease, type 2 diabetes, asthma, and Alzheimer’s disease. Studies suggest that intermittent fasting reduces inflammation markers and risk factors for cardiovascular diseases such as homocysteine, CRP, and TC/HDL ratio. It was established that during fasting, monocytes, a collection of pro-inflammatory cells, go into sleep mode and are less inflammatory than the cells that had been fed.
- Brain Health
A 2020 study published in the Journal of The Alzheimer’s Association showed the positive effects of IF in reducing neuroinflammation, meaning that IF may protect the brain from the effects of aging and disease. Another 3-year progressive study established that older adults who practiced IF regularly had better cognitive scores and reverted to better cognitive function groups (successful aging and normal aging). Therefore, long-term intermittent fasting may help improve one’s memory, overall cognition, and executive function, although further research is needed.
- Heart Health
Intermittent fasting can be good for the heart. Human studies show that IF could positively impact cardiovascular health by minimizing risk factors such as hypertension, obesity, dyslipidemia, and diabetes. This eating pattern has also been associated with improved outcomes after a cardiac event, although data is limited .
Side Effects Of IF
According to Harvard Health, IF may:
- Make you feel sick by experiencing headaches, crankiness, lethargy, and constipation depending on the length of the fasting period.
- Make you overeat because your appetite hormones and hunger center in your brain go into overdrive when you are deprived of food during fasting.
- Cause older adults to lose too much weight.
- Be dangerous if you are on certain medications; therefore, consult your doctor before trying it.
Low-Carb Diets
A low carbohydrate weight loss plan involves the consumption of low carb, high-fat foods. Usually, simple natural, simple refined, complex natural, and complex refined carbs such as grains, fruits, legumes, bread, sweets, pastas and starchy vegetables, and in some cases, nuts and seeds are limited. Still, some diet plans permit small quantities of whole grains, fruits, and vegetables. While it is recommended that carbohydrates should constitute 45% to 65% of your total daily calorie intake (between 900 and 1,300 calories if you consume 2,000 calories a day), a low-carb diet involves consuming as little as 0.7 to 2 ounces (20 to 57 grams) of carbohydrates, providing 80 to 240 calories a day.
An excellent example of a low carb high-fat intake is the ketogenic diet which starts by reducing your daily carb intake to about 20-50 grams, creating a carbohydrate deficiency that signals the body to start a metabolic process called ketosis. During ketosis, your body breaks down fat to form substances known as ketones, forcing the body to rely on fats instead of glucose as its primary energy source.
Benefits Of Low-Carb High-Fat Diet
Low carb diets promote a heavy intake of healthy fats, fewer carbs, and a substantial amount of protein, triggering the body to extract energy from alternative fuel sources (especially fats). The benefits of this include:
- Weight Loss
Cutting out carbs is one of the most effective ways for weight loss. People on a low-carb diet might lose weight faster than people on a low-fat diet because they will be consuming fewer calories. A low-carb diet may also minimize appetite and calorie intake, and with time, the body adapts to a lower appetite. A randomized controlled trial of a low-carbohydrate diet for weight loss established that satiety (fullness) may be better preserved on a low-carbohydrate diet than a low-fat diet. Eating restricted amounts of carbohydrates decreases appetite-stimulating hormones such as insulin and ghrelin and might lower the risks of metabolic syndrome.
- Reduced Blood Sugar And Insulin Levels
Low carb and keto diets are helpful for people living with diabetes and insulin resistance. According to Diabetes UK, reducing carb intake may help eliminate the spikes and crashes in sugar levels after meals, ease diabetes management, reduce HbA1c levels, minimize the risk of severe hypoglycemia, and prevent diabetes complications. Other advantages of such a meal plan include clarity of thought enhancement, improved skin complexion, and reducing tiredness through the day.
- May Lower Blood Pressure And Improve Heart Health
A study published in the International Journal of Environmental Research and Public Health concluded that low carb diets effectively lower high blood pressure, one of the cardiovascular risks that people with type 2 diabetes or impaired glucose tolerance face. By eating a low-carb diet, one makes healthy food choices, including healthy fats that help with cholesterol control, which translates into significant cardiovascular protection. A keto diet could also help in lowering low-density lipoprotein (LDL) (bad cholesterol) and raising high-density lipoprotein (HDL) (good cholesterol) levels
Side Effects
The downsides of this eating plan, according to the Mayo Clinic, include:
- Sudden and drastic reduction in carbs may cause temporary side effects like constipation, muscle cramps, bad breath, fatigue, and headache.
- Long-term carbs restriction may result in vitamin or mineral deficiencies and gastrointestinal disturbances.
- Eating large amounts of fat and protein from animal sources may put you at higher risk of heart disease or certain cancers. Therefore, you should pay attention to the fats and proteins you consume while on this diet and restrict foods with saturated and trans fats (for example high-fat dairy products and meat) which may increase heart disease risk.
Combining Keto & Intermittent Fasting: Benefits + Challenges
Although they may seem different on the surface, Keto and IF share many similarities. They both encourage the body into a Ketogenic state, and have the potential to increase fat burning. There’s also a lot of crossover between the potential wellness benefits, from heart health to insulin sensitivity.
You may be wondering whether it’s safe and effective to combine the two — extending your fasting window, and consuming a high-fat diet during your eating window.
The good news is that because both diets work via similar underlying mechanisms, they have the potential to complement each other. Keto and IF act synergistically towards the same end goal – making the body more adept at burning fat as a fuel. You might also find that the common challenges of each diet are canceled out when you combine them together:
- Restricting food intake through IF may make it easier to get into and stay in ketosis, as this kick-starts the depletion of carbohydrate levels.
- A Ketogenic diet may make intermittent fasting feel easier as your body becomes more fat-adapted, and you feel more satiated from consuming higher-fat foods.
- If you’re fairly new to Keto, you may find that IF helps you stick to the diet, as you have fewer meals to think about and prep.
That being said, there are some potential drawbacks to be aware of:
- You will likely find it challenging if you are brand new to both Keto and fasting, as it’s a big shift from the norm. You may be better off starting with one thing at a time.
- Fasting is not suitable for pregnant women, children, and people with eating disorders.
Which Fasting Protocol is Right For You?
There are numerous fasting protocols to choose from, each with their individual benefits and drawbacks. Here are some of the most popular:
Lean Gains – 16:8
As the name suggests, the 16:8 fast involves a 16 hour fasted window, followed by an 8-hour feed. This can be achieved by compressing your normal mealtimes, or simply by skipping breakfast and having two meals a day. It’s a great introductory protocol suitable for both beginners and more experienced fasters, and can be performed on a daily basis.
Warrior Diet / OMAD – 20:4
The Warrior Diet or One Meal a Day protocol involves fasting for 20 hours of the day. It’s a popular choice after adjusting to the 16:8 protocol. Aside from helping you get deeper into a fasted state, this protocol is popular because it can save time and allows you to binge on one big meal in the evening. Some practice OMAD daily, but others prefer using it on a weekly or monthly basis.
Alternate Day Fasts
Alternate day fasts are one of the most commonly studied protocols in the fasting literature. As the name implies, it involves a day of eating, followed by a day of no food, or a day of reduced calories. Alternate day fasts are often used by people seeking significant weight loss, or to help manage a health condition. Because the fasting period is typically around 24 hours or longer, autophagy should kick in, meaning you may get some of the proposed longevity benefits of fasting.
5:2 Diet
The 5:2 diet is less of a true fast, and more of a “Fasting Mimicking Diet”. It involves five days of normal eating, followed by 2 days eating less than 500 kcal. This can be effective for weight loss, but because you do not enter a completely fasted state, may not provide some of the other potential benefits of fasting.
Extended Water Fasts
Water fasts of 24+ hours are typically used in an attempt to manage or combat long term illnesses like autoimmune conditions, or for significant weight loss. Long fasts are not suitable for everyone, and should only be completed in a supervised medical setting.
How to Supercharge Your Keto Diet With Intermittent Fasting
If you’re interested in merging both dietary protocols, below you’ll find a sample daily schedule combining Keto with 16:8 (the most beginner-friendly form of fasting).
Day 1:
8:00 PM – Dinner – Keto Alfredo Chicken Bake
10:30 PM – Bed
Day 2:
7:00 AM – Wake, Meditate, Walk or Yoga
12:15 PM – Breakfast – Low Carb Overnight Chia Almond Pudding
4:00 PM – Lunch – Keto Lemon Chicken Meal Prep
6:00 PM – Evening Workout
8:00 PM – Dinner – Keto Turkey Chili
After day 2, simply repeat this daily schedule, following the same approximate eating and fasting windows, and substituting in whatever Keto-friendly meals appeal to you.