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Julie Hambleton
Julie Hambleton
May 28, 2024 ·  7 min read

What Happens to Your Cholesterol When You Only Eat One Meal Per Day?

For decades we were told to eat three meals per day: Breakfast, lunch, and dinner. Then different information started coming out about eating more often but smaller portions and other various “fad” diets. The most recent eating trend to pick up steam? Intermittent fasting. Many people are jumping on the intermittent fasting train, claiming that it has helped them lose weight and manage various other health problems. With so many formats for it, it is hard to know where to start. One meal a day (OMAD) diet is a type of intermittent fasting that limits calorie consumption to one meal per day. However, before starting this kind of diet plan, it’s important to understand both the benefits and potential risks to your body.

What is Intermittent Fasting?

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Intermittent fasting is a type of dieting that involves restricting calorie intake during specific periods of time. Typically, it involves fasting for a specific period and then eating within a specific window of time. Some people fast for an entire day while others fast for a few hours or a few days at a time. Intermittent fasting helps limit calorie intake, and some research shows it may help to improve metabolic health and promote weight loss. (1)

Read More: Experts Say These Are The 5 Worst Foods For Your Cholesterol

What is the OMAD diet?

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The OMAD diet is a type of intermittent fasting that restricts calorie consumption to only one meal per day. This means that individuals eat only once, either at lunchtime or dinnertime. People who follow the OMAD diet plan have a short window of time to consume their daily allowance of calories. These diets typically range from 500 to 1,500 calories. While some people will allow a small snack or two in addition to the one meal per day, the most extreme OMAD followers consume calories only during their one meal.

Benefits of OMAD Diet

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This is probably sounding pretty crazy, especially if you have never tried any other version of fasting before. It is true that this is a fairly extreme version of intermittent fasting. Though admittedly bizarre-sounding, there are some benefits to the OMAD diet.

1. Weight Loss

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By limiting calorie intake to one meal per day, the OMAD diet creates a calorie deficit that can lead to weight loss. This is because the fewer calories you consume, the more weight you lose. Eating just one meal per day is fairly calorically restrictive. You will be hard-pressed to consume a typical day’s worth of calories in just one meal, especially if you are trying to eat healthy foods. A study conducted in healthy adults found that restricting calorie intake to a 4-hour time period in the evening led to significantly greater body fat loss than when eating three separate meals throughout the day. (2)

2. Improved Health Markers

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OMAD may also improve health markers by reducing blood sugar levels, lowering inflammation, and reducing the risk of disease. This is because the body is able to process food more efficiently when it’s not constantly being bombarded with calories. This can lead to improved insulin sensitivity, which is important for preventing diabetes, chronic inflammation, and other metabolic disorders. (3)

3. Simplifies Meal Planning

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The OMAD diet plan simplifies meal planning since one only needs to plan for one substantial meal that satiates the body completely. That certainly frees up time, mental space, and budget that would normally be spent planning, purchasing, and preparing food.

Read More: 4 Potential Health Benefits of Okra (Cholesterol, Blood Sugar and More)

Drawbacks of OMAD Diet

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While there are definitely some benefits to this restrictive way of eating, there are certainly drawbacks, too. It is really important to consider your lifestyle and nutrition needs before you attempt this diet, as it is certainly not for everyone. It is also important to monitor your health and how you are feeling, as with any new diet plan.

1. Nutrient Deficiency

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Eating three meals a day provides three opportunities for eating a variety of foods, particularly a larger variety of fruits and vegetables. Consuming fewer meals means there may be a higher chance of missing out on essential nutrients like vitamins, minerals, and fiber.

2. Loss of Lean Mass and Bone Density

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This is a very important drawback to consider, as it can have a far-reaching impact on your health. Research shows that while participants in a trial on this method lost fat, they also lost lean mass (aka muscle) and bone density. Losing muscle means losing certain aspects of your physique that you may cherish. It will also mean a loss in strength. Losing muscle mass will also eventually lead to a slower metabolism, as muscle is active and burns fat even while at rest. Losing bone density could also cause serious health problems, especially for women who are already at a greater risk of osteoporosis. (4)

3. Hunger and Fatigue

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Skipping meals can lead to hunger and low energy which may affect concentration levels, mood, and productivity. This is what makes this diet difficult for those who have physically and/or mentally demanding jobs or who lead a very active lifestyle. For example, this diet is not recommended to anyone with performance goals related to exercise, such as running, cycling, swimming, or activities such as CrossFit. (5)

4. Difficulty Sticking to the Plan

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Let’s be honest: This diet isn’t really sustainable, nor is it necessarily intended to be. It can be difficult to stick to the OMAD diet long-term, leading to a higher likelihood of binging and overeating. Many struggle with cravings for heavy, sugar and fat-laden foods when it comes to finally eat, rather than nutrient-dense foods.

Read More: How to Help Lower Cholesterol Without Medication

5. Side Effects

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Following an OMAD diet has its potential risks and side effects. These include nausea, dizziness, irritability, and constipation. OMAD decreases glucose tolerance in some individuals, leading to increased hunger and fat storage. It has also been found to actually increase both levels of total cholesterol and the LDL (bad) cholesterol. (6)

6. Takes Away the Joy of Eating

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Since the beginning of time, humans have been gathering together to eat, drink, and be merry. Such a heavily restrictive diet will mean many social situations where everyone else will be enjoying a meal together and you will be… drinking a glass of water. One of the most important aspects of health and longevity is social interaction and have friends and community around you, as well as low stress levels. Having to attend a social situation in which you cannot eat while everyone else is is not only isolating, but stressful.

How often should you be eating and when for optimal health?

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Ultimately, there is no one-size-fits-all answer to this question. Some people do well with three meals a day with snacking while others benefit from intermittent fasting with one to two meals. This depends on various factors such as individual metabolic needs and overall health goals. For example, a marathon runner with an active day job is going to have much higher caloric needs than, say, a sedentary office worker. The needs and optimal diet will also change depending on age, biological sex, and so on. The best thing to do is to work with a doctor and a dietitian who can help you find a diet plan that will help you to reach your health goals and still allow you to enjoy your life.

The Bottom Line

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The One Meal a Day (OMAD) diet is a type of intermittent fasting that can help promote weight loss and improved health markers. However, there are potential drawbacks, such as a higher likelihood of nutrient deficiency and difficulty sticking to the plan long-term. It’s important to carefully consider the benefits and risks of the OMAD diet and to consult with a healthcare professional before starting any new diet plan. Overall, incorporating healthy, nutrient-dense foods in a sustainable meal plan is the best way to achieve optimal health.

Read More: Scary New Study: Plastic Bottles Left in the Sun Leach Cancer-Causing Chemicals Into Water


  1. Impact of Intermittent Fasting on Metabolic Syndrome and Periodontal Disease—A Suggested Preventive Strategy to Reduce the Public Health Burden.” MDPI. Sameena Parveen and Yaser Ali Alhazmi. November 5, 2022.
  2. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults.” NCBI. Kim S Stote, et al. April 2007.
  3. Intermittent Fasting in Cardiovascular Disorders—An Overview.” NCBI. Bartosz Malinowski, et al. March 2019.
  4. Extreme Fasting: What Is ‘One Meal a Day’ Actually Doing to Your Body?.” Science Alert. Amanda Avery. April 14, 2023.
  5. Potential Benefits and Harms of Intermittent Energy Restriction and Intermittent Fasting Amongst Obese, Overweight and Normal Weight Subjects—A Narrative Review of Human and Animal Evidence.” NCBI. Michelle Harvie and Anthony Howell. January 19, 2017.
  6. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults.” NCBI. Kim S Stote, et al. April 2007.