Eating one meal a day, whether you're doing it for religious reasons or as a special diet, is a form of fasting. It's a difficult way to go about losing weight, but if you're the type of person who thrives on structure, it can help.
Smaller, More Frequent Meals
Some diets advocate for more frequent, smaller meals throughout the day for weight loss. These diets have some merits, but the jury is still out on whether or not they're best.
A January 2015 study published in Nutrition Reviews showed that in some cases, eating more frequent, smaller meals was better than a single, large meal, but most of the time, the distinction was indefinitive. If you've already tried the smaller, more frequent meal approach, it might be time to try something else.
Intermittent Fasting Diet
Intermittent fasting is a popular diet trend that advocates fasting for different lengths of time. You can fast all morning into the afternoon or evening, then consolidate all of your meals into a few hours. You can fast one or two days per week when you don't eat anything. You can also fast every other day for a certain period of time.
This style of fasting has grown in popularity. It promises to help you lose weight and improve your health by reducing the amount of food you eat. The act of fasting can also help improve some markers of health according to a September 2015 study published in Nutrition Reviews.
The researchers found that, in addition to lowering overall weight and bodyfat percentage, fasting reduced cholesterol and triglyceride levels, decreasing your risk for heart disease.
Read more: 13 DOs and DON'TS of Intermittent Fasting
The Hard Part: Fasting
Trying intermittent fasting requires discipline. At first, you'll be hungry during your period of fasting. Some people prefer to fast in the morning through to the afternoon or evening, at which time they'll have one or two meals.
Fasting is used for many reasons. Some people simply dislike eating breakfast. They're not hungry in the morning or don't have time to cook and eat food. Some people use it to lose weight and find that it works well.
Deciding When to Eat
Eating only one meal per day will be a challenge, but if it works for you, it can be an effective strategy. First, you'll have to figure out when to eat your meal. According to a February 2019 study in Appetite, most people who follow intermittent fasting save their meal for dinner.
Whatever time of day you choose, try to stick to the same time. To maximize the effects of fasting, try to keep your meals more than 16 hours apart. According to an April 2019 study published in the Proceedings of the Nutrition Society, fasting over 16 hours is better for decreasing fat mass and improving insulin sensitivity.
Be aware that eating one large meal may lead to acid reflux, a condition in which stomach acid comes up your esophagus. According to Harvard Health Publishing, eating large meals and lying down after eating can cause acid reflux, so this could impact your decision as to when you eat your meal — too close to bedtime could cause problems.
Consider the Calories You Need
For your only meal of the day, determine how many calories you need and how to get all of your nutrients for the day. Calories are still important because you can gain weight even if you're only eating one meal per day. However, it's more difficult to eat enough calories to gain weight in one sitting.
It's possible to consume too many calories even when you're eating only one meal a day. If you're trying to lose weight, your goal should be to consume fewer calories than you take in. To figure out how many calories you should be eating per day, you can use a calorie tracking app like MyPlate.
Get All Your Nutrients
Once you figure out how many calories you need to eat per day to lose weight, determine how much of that should come from fat, protein and carbs. To lose weight, ACE Fitness recommends 45 to 50 percent of your total calories come from carbohydrates, 25 to 30 percent come from protein and 20 to 25 percent come from fat.
You can also see a registered dietitian, who can help customize your daily meal to fit your needs. A dietician or nutritionist can also make sure that you get enough nutrients like vitamins, minerals and fiber.
Sluggishness From Fasting
Another danger of fasting is that you lose energy. Without eating all day, you are likely to get tired and hungry. A November 2016 study published in Proceedings of the Nutrition Society showed that people who skipped breakfast tended to have less energy throughout the day. This can hinder your weight loss if it makes you less active or less motivated to work out.
Learning From Ramadan
Intermittent fasting is only one example of fasting. There's another form that's practiced worldwide for religious reasons: Ramadan. Muslims celebrate Ramadan in the ninth month of the Islamic calendar. During Ramadan, you're not supposed to eat or drink anything while the sun is still up, for a period of one month.
Millions across the world fast for one month in observance of Ramadan. Due to the time restrictions on eating, many consume only one meal per day. This practice gives scientists a chance to study the effects of fasting.
A January 2018 study published in the American Journal of Clinical Nutrition showed that fasting during Ramadan didn't have any effect on weight loss or metabolic rate, which is the number of calories you burn throughout the day through natural processes like digestion. The researchers noted that the only observed effects were decreased activity level and less sleep, which could be due to the fact that practitioners can only eat during nighttime hours.
The researchers also noted that other studies in which Muslims lost weight during Ramadan were probably due to the fact that they ate less food. It's simply more difficult to eat all the food required throughout the day in one sitting.
Read more: How Intermittent Fasting Can Get You Lean
Adding a Second Meal
Eating one meal per day might work for you, but it's not necessarily the best way to go about losing weight. If your goal is to have a lean, muscular physique, eating at least two meals per day with 30 to 45 grams of protein in each meal is best, according to a December 2016 study published in Clinical Nutrition. According to the researchers, this is the best way to maintain and build muscle.
- Nutrition Reviews: "Effects of Meal Frequency on Weight Loss and Body Composition: A Meta-Analysis"
- Nutrition Reviews: "Effects of Intermittent Fasting on Body Composition and Clinical Health Markers in Humans"
- ACE Fitness: "How to Determine Macronutrient Needs Based on Goals"
- Proceedings of the Nutrition Society: "Is Breakfast the Most Important Meal of the Day?"
- The American Journal of Clinical Nutrition: "The Effects of Ramadan Fasting on Activity and Energy Expenditure"
- Clinical Nutrition: "Per Meal Dose and Frequency of Protein Consumption Is Associated With Lean Mass and Muscle Performance"
- Harvard Health Publishing: "9 Ways to Relieve Acid Reflux Without Medication"
- Appetite: "Breaking the Fast: Meal Patterns and Beliefs About Healthy Eating Style Are Associated With Adherence to Intermittent Fasting Diets"
- Proceedings of the Nutrition Society: "The Role of Intermittent Fasting and Meal Timing in Weight Management and Metabolic Health"
- Islamic Association of Raleigh: "Rules of the Fasting of Ramadan"
- Cornell Health: "Tips for Healthy Ramadan Fasting"