Take a 1-min quiz to get a Personal Meal Plan Male Female

Three-Week Diet Plans: Getting Your Nutrition Back on Track

When it comes to weight loss, many people often feel that working out is the hardest part of the process. While getting into and sticking to a workout routine can be difficult, especially for beginners, very few people talk about how hard sticking to a healthy diet is.

The simple and undeniable truth about weight loss is that you cannot out-exercise a bad diet. No matter how much cardio you do, how many weights you lift, or how many Pilates classes you attend, you won’t see any desirable results if your diet is not where it needs to be.

But how do you stick to a weight loss diet in the long term? This is where three-week diet plans come in. Read on to learn how you can turn your diet and fitness journey around using three-week diet plans to lose weight.

What Is a 3-Week Diet Plan?

A three-week weight loss diet plan is a 21-day eating plan that focuses on healthy and nutritionally-dense foods that can help with weight loss. Although long-term healthy eating is the true goal, breaking it up into 3-week chunks can help the journey feel less daunting. The only major rule that should be followed on a 3-week diet plan to lose belly fat and experience weight loss is you should eat at a calorie deficit. 

Being on a calorie deficit simply means that you consume less energy (through food and drink) than your body burns in a day. This deficit creates a negative energy balance in the body, forcing the body to turn to burning its stored fats for more energy. 

Research over the years has shown that a negative energy balance in the body can lead to both a reduction in abdominal fat and weight loss (1, 2, 3, 4). 

How to Find Your Calorie Deficit for Your Three-Week Weight Loss Eating Plan

Please note that due to the multiple factors that influence calorie needs such as age, physical activity, and sex, (5) it’s difficult to say how much your individual calorie intake should be. However, a good place to start is by simply cutting 500 calories from your normal calorie intake.

If you don’t know how many calories you consume on a daily basis, we recommend that you use the BetterMe App to help you calculate. Simply download the app, log in, and input everything you eat and drink into the app. 

After about a week, you can have a good idea of your average daily calorie intake. Subtract 500 from that number and this new number will be the approximate number of calories you should be eating while following the three-week diet plan.

Read More: Mediterranean Diet 30-Day Meal Plan: The Beginner’s Guide With Clear-Cut Answers About This Diet Plan

What to Eat on a Three-Week Diet

The best part about healthy three-week diet plans is that they don’t limit any foods on the macro foods list. While you can alter the foods depending on your dietary needs or restrictions, such as lactose intolerance, vegetarian or vegan restrictions, or keto dietary rules, the diet simply urges you to eat a variety of nutritious foods from all food groups. 

Some tips to follow to ensure your eating habits are as healthy and effective for weight loss as can be on this plan include:

Starchy vegetables Whole grains Protein (animal and plant-based) Dairy/milks
Potatoes Black and brown rice All kinds of beans Milk
Corn Quinoa Poultry Yogurt
Plantain Millet Protein powders Cottage cheese
Butternut squash Buckwheat Tofu Plant-based milks
Cassava Bulgur Seitan
Yams Oats Eggs
Green beans Whole-wheat bread Lentils
Sweet potatoes Whole-wheat pasta Lean beef
Fish and seafood
Healthy fats Fruits Non-starchy vegetables Nuts and seeds
Fatty fish All kinds of berries Zucchini Peanuts
Avocados Bananas Cabbage Almonds
Olive oil Apples Tomatoes Chia seeds
Other vegetable oils Watermelon Broccoli Hemp seeds
Pineapples Leafy greens Macadamia
Peaches Cauliflower Pistachios
Oranges Daikon Cashews
Grapefruit Eggplant Pumpkin seeds
Cucumbers Sesame seeds
Onions
Mushrooms
Bell pepper
  • Eat All the 5 Main Food Groups

This means you should have a portion of fruit and vegetables, dairy products (or plant-based products for those with dietary restrictions), protein (both animal and plant-based, unless vegetarian or vegan), healthy fats, and fiber-rich carbohydrates such as whole grains and legumes (6).

  • Limit Your Added Sugar Intake

Not all sugar is bad – natural sugars that are found in fruits and vegetables are okay. What you need to be wary of is added sugars. Studies have shown that a higher added sugar intake is associated with weight gain and a greater risk of obesity (7, 8).

  • Stay Hydrated

Make water your friend. Drinking water prevents dehydration, particularly if you choose to exercise during these 3 weeks. Research has also shown that it can help with weight loss through appetite suppression, increased thermic effect, and reduced sugar intake, particularly if you opt to replace sugary drinks with water (9, 10).

  • Reduce Your Salt/Sodium Intake

Research has suggested that a higher intake of salt may increase the risk of obesity in children, teens, and adults. Some studies have found that people who consume more salt in their diets tend to have a higher BMI than those who consume less salt, but their waist circumference is also larger (11, 12).

Whether you’re a workout beast or just a beginner making your first foray into the world of fitness and dieting – BetterMe has a lot to offer to both newbies and experts! Install the app and experience the versatility first-hand!

What to Add to Your 3-Week Diet Food List

To make your grocery shopping and meal/food planning easier, here’s a table of some of the foods you should eat while on this diet:

 

Feel free to add your favorite herbs and spices to the above list. Not only do they have a negligible amount of calories, they also make food taste better. There’s no point in eating bland food in the name of weight loss.

You can also remove and replace any foods in accordance with your dietary needs and preferences. For example, those who are following a ketogenic plan and hope to use a three-week diet plan to help them complete a 30-day keto challenge wouldn’t eat most starchy carbs or whole grains and are only allowed berries as fruits. Therefore, they can’t eat everything on this list.

Modify the list to suit your needs.

Read More: Smoothie Diet Plan: Smoothie Diet Plan To Stop The Pounds From Piling On

What Is the Best Three-Week Diet?

Despite the popularity of many weight loss diets, some of which have scientific research backing that shows how effective they are, scientific reviews agree that there’s no one diet that stands above the rest. There simply isn’t a “best diet for weight loss” (13, 14). 

Researchers are in agreement that while popular weight loss eating plans such as vegetarianism, low-fat diet, high-protein diet, the Mediterranean diet, paleo, and keto all have proven results for weight loss, the best diet for good health and weight management is one that is individualized to a person’s preferences.

If you’re confused about where to start, researchers simply advise you to stick to a nutritionally hypocaloric diet, which simply means a diet that is low in calories. Such a meal plan is made up of (13):

  1. Mainly whole-grain products
  2. At least five servings per day of fruits and vegetables
  3. Moderate amounts of dairy and meat products
  4. Limited amounts of foods that are high in fat or added sugar or contain few nutrients

If you struggle to even flirt with the idea of giving up your favorite foods or working out till your legs give way – the BetterMe app is here to breathe a fresh perspective into the way you view the weight loss process! Check out the app and experience the fun side of fitness and dieting with BetterMe!

How Much Weight Can You Lose on a 3-Week Diet?

If you’re eating within your calorie deficit goal, exercising, sleeping enough, and have no underlying health issues that make weight loss harder than it needs to be, you will likely lose between 3 and 6 pounds in 3 weeks (15). Most health authorities suggest a pace of 1-2 pounds per week for safe and sustainable weight loss. 

How Long Does it Take to Get in Shape?

There are too many variables that affect weight loss to be able to provide a direct answer to this (16, 17). Weight loss and muscle growth are individualized to a person, but improving your diet, sleeping enough, and exercising using both cardio and weight training can help you achieve your goals sooner.

How to Reduce Belly Fat in 3 Weeks

Unless you have very little body fat, it’s impossible to lose all your belly fat in just 3 weeks. Any diet or workout routine that promises such miraculous results is simply a fad diet that will end up causing you more harm than good. 

Losing belly fat, as with weight loss in general, takes time. Be patient, exercise (full-body workouts not just stomach/core workouts), and eat a healthy calorie deficit diet. The results may take a while to show but they will eventually come.

FAQs

  • Can I lose 10 lbs in 3 weeks?

There’s no healthy way to lose 10 lbs in just 3 weeks. As previously mentioned, the highest amount of weight you should aim to lose in this time frame is 6 lbs – using the rate of a loss of 1 to 2 pounds a week.

  • Does lemon water burn fat?

No, water doesn’t burn any fat. This is a myth that has been circulated so much that it tends to sound like fact. The only way to burn fat is through exercise, which burns calories inducing fat and weight loss, or through a calorie deficit diet that makes the body burn its stored fats for energy. This leads to fat loss.

However, drinking lemon water can be good for your health. If drinking lemon water makes you drink more water than usual, then you’re more likely to be properly hydrated. Drinking water may also trigger a temporary metabolic rate increase, which helps the body burn a few more calories (18, 9). Lemon juice is also rich in citric acid, vitamin C, and polyphenols, which are good for your general health and may even have some anti-aging effects (19).

  • Should you follow a three-week liquid diet?

No, you shouldn’t. Such an eating plan and any other three-week detox diet is not good for your health as it’s too low in calories and doesn’t provide adequate nutrition. Such diets also just make you lose water weight and not fat, so as soon as you return to eating as normal, all the lost weight will come back.

  • Should I take part in a three-week metabolic rate diet?

If the diet is balanced, recommends exercise, increased water intake, the consumption of enough calories, and increased protein intake, and emphasizes the importance of sleep, then yes, you can. At the end of the day, these are the factors that help with a metabolism reset.

  • How can I get shredded in 3 weeks?

For most people, this time frame is too short. It may take you months or even over a year to get a shredded physique. It is largely dependent on your starting point, the intensity of your workout plan, and your diet. 

The Bottom Line

The best three-week diet plans are those that emphasize a healthy calorie deficit. The diet shouldn’t cut off entire food groups, nor should it advocate for minimal calorie consumption in the name of weight loss.

If you choose to follow any three-week diet plan (or make one yourself), we suggest that you make or find one that is healthy. Adding exercise to your routine is also a good idea as it helps improve your cardiovascular health while also promoting calorie-burning, which will help you get in shape faster.

DISCLAIMER:

This article is intended for general informational purposes only and does not serve to address individual circumstances. It is not a substitute for professional advice or help and should not be relied on for making any kind of decision-making. Any action taken as a direct or indirect result of the information in this article is entirely at your own risk and is your sole responsibility.

BetterMe, its content staff, and its medical advisors accept no responsibility for inaccuracies, errors, misstatements, inconsistencies, or omissions and specifically disclaim any liability, loss or risk, personal, professional or otherwise, which may be incurred as a consequence, directly or indirectly, of the use and/or application of any content.

You should always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or your specific situation. Never disregard professional medical advice or delay seeking it because of BetterMe content. If you suspect or think you may have a medical emergency, call your doctor.

SOURCES:

  1. Fat loss depends on energy deficit only, independently of the method for weight loss (2007, pubmed.ncbi.nlm.nih.gov)
  2. The Importance of Energy Balance (2013, ncbi.nlm.nih.gov)
  3. Metabolic adaptations during negative energy balance and their potential impact on appetite and food intake (2019, pubmed.ncbi.nlm.nih.gov)
  4. Negative Energy Balance Induced by Exercise or Diet: Effects on Visceral Adipose Tissue and Liver Fat (2020, mdpi.com)
  5. Calories: Total Macronutrient Intake, Energy Expenditure, and Net Energy Stores (n.d., ncbi.nlm.nih.gov)
  6. Healthy Eating Plan (n.d., nhlbi.nih.gov)
  7. The Dose Makes the Poison: Sugar and Obesity in the United States – a Review (2019, ncbi.nlm.nih.gov)
  8. Added sugar intake is associated with weight gain and risk of developing obesity over 30 years: The CARDIA study (2024, sciencedirect.com)
  9. Effect of excessive water intake on body weight, body mass index, body fat, and appetite of overweight female participants (2014, ncbi.nlm.nih.gov)
  10. Water Intake and Adiposity Outcomes among Overweight and Obese Individuals: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (2024, mdpi.com)
  11. Sodium intake may promote weight gain; results of the FANPE study in a representative sample of the adult Spanish population (2014, pubmed.ncbi.nlm.nih.gov)
  12. Relationship of Sodium Intake with Overweight/Obesity among Chinese Children and Adolescents: Data from the CNNHS 2010–2012 (2012, ncbi.nlm.nih.gov)
  13. Weight-Loss and Maintenance Strategies (n.d., ncbi.nlm.nih.gov)
  14. Optimal Diet Strategies for Weight Loss and Weight Loss Maintenance (2020, ncbi.nlm.nih.gov)
  15. Steps for Losing Weight (2023, cdc.gov)
  16. Factors That Influence Body Weight (n.d., ncbi.nlm.nih.gov)
  17. Factors affecting weight loss variability in obesity (2020, sciencedirect.com)
  18. Effect of ‘Water Induced Thermogenesis’ on Body Weight, Body Mass Index and Body Composition of Overweight Subjects (2013, ncbi.nlm.nih.gov)
  19. Effects of lifelong intake of lemon polyphenols on aging and intestinal microbiome in the senescence-accelerated mouse prone 1 (SAMP1) (2019, ncbi.nlm.nih.gov)
Share
150 million people
have chosen BetterMe

Great app!

Сustomer

Great app!! Easy to navigate through! I like that I can log my food to determine calorie intake. I like the achievement levels, perfect music too!

Love this app

Stephanie
Love this app. Makes it easy to track with delicious recipes. No need to think about what to cook each meal. And there are so many exercises so you can do something different every day.

BetterMe is a fantastic program…

Barb K.
BetterMe is a fantastic program with outstanding people who care about their clients. The curriculum is amazing and produces excellent results. Thank you BetterMe.