21 Day No Junk Food Challenge (Are You Up to the Challenge?)

Weight Loss & Diets | Written by Nathan Petitpas | Updated on 31 May 2024

A man is refusing burgers, pizza, and ice cream as he participates in a few days of no junk food challenge, with a calendar behind him showing three weeks marked off.

Junk food has nearly become a delicacy and it surrounds us no matter where we go; we see McDonalds on every street corner, candy bars at the end of every grocery aisle, and gummy bears at the gas stations.

However, the 21 days no junk food challenge shows you that eliminating heavily processed foods is possible and that you can take back control of your eating habits. It’s just three weeks, and you can do it!

How Do You Start The 21 Days No Junk Food Challenge?

First, it’s important to know the rules of the challenge. It would be discouraging to start and find out halfway through that a forbidden food has been a primary component of your diet, so take some time to research and fully understand the rules.

Furthermore, understand that going without processed and fast food for 21 days is a challenge, hence the name. Make sure to identify sources of motivation before taking the challenge. Whether it’s something simple like losing weight, lowering cholesterol and improving heart health, or building a better relationship with food, establishing motivation will help to push through those difficult times.

Consider asking friends and family to take on the challenge with you. Companions will provide motivation to each other and help keep everyone accountable. Start a group chat to discuss daily struggles and stay on track.

Rules Of The 21-Day No Junk Food Challenge

The rules of the challenge are simple and straightforward. Do your best to avoid consuming foods that are processed, pre-packaged, or contain added sugar or white flour. Replace these with foods that are whole and in their natural state. This is not an easy task that teaches you ways to lose weight without trying. The challenge will require effort, self-discipline, and acquiring knowledge of how to find healthy alternatives.

Junk Food List

Below is the list of foods not permitted for the challenge. Put forth your best effort to eliminate these foods and replace them with nutritious whole foods.

  • Candy
  • Chocolate
  • Chips
  • Crackers
  • Cookies
  • Cake
  • Pastries
  • Donuts
  • Muffins
  • White bread
  • Fast Food
  • Nutella or processed peanut butter
  • Ice cream
  • Carbonated drinks
  • Sports drinks (Gatorade, Powerade, etc.)
  • Deep-fried foods
  • Processed foods (foods that are prepackaged or add sugar, salt, fat, artificial colors, preservatives, or other additives)
  • Food with refined sugar or white flour

Healthy Food List

Now that the prohibited foods list is established, it’s time to learn about all the great whole foods that are included! One of the goals of this challenge is to show that a healthy alternative is always available and that there are plenty of foods that are both nutritious and delicious.

Healthy Proteins

  • Chicken breast or thighs
  • Pork chops
  • Beef (steak, lean ground beef)
  • Lamb
  • Fish
  • Shellfish
  • Eggs
  • *All meat and seafood must start in their raw, natural state. Do not buy anything that’s been precooked, cured, or treated with preservatives or flavorings (deli meat, bacon, sausage, etc.)

Healthy Sides

  • Potatoes/Sweet potatoes
  • Beans and legumes
  • Rice
  • Quinoa
  • Couscous
  • Barley
  • Millet
  • Whole grain pasta

Healthy Snacks

  • Fruits
  • Vegetables
  • Nuts and seeds
  • Natural nut butter
  • Yogurt
  • Cottage cheese
  • Hummus
  • Whole-grain crackers, bread, and cereal
  • Granola (exclude mixes with chocolate)
  • Homemade trail mix

Healthy Drinks

  • Water
  • Milk
  • Minimally processed dairy alternatives (coconut milk, almond milk, oat milk)
  • Herbal teas (Must be brewed from tea bags)
  • Black coffee
  • More water
  • Gatorade zero can be good for weight loss since it’s a low calorie and tasty alternative to sugary drinks

Tips On How To Stop Eating Junk Food Sugar

Junk food from McDonald's fast-food chain containing french fries, dipping sauce, chicken nuggets, and burgers.

Accepting the challenge is a great first step, but now it’s important to set yourself up for success and learn how to stop the urge eating junk food and sugar. It’s understandable to be eager to start, but doing a bit of due diligence before beginning the challenge will allow participants to get more out of their efforts.

Shop Smart

One of the simplest ways to avoid forbidden foods during the 3 weeks of no junk food challenge is by grocery shopping strategically. Make a list before heading into the store to avoid wandering through the aisles and grabbing unnecessary items. It’s also recommended to stick to the outside aisles along the walls of grocery stores as this is typically where items such as fresh fruits, vegetables, meats, and fish will be located [1].

Cook Meals At Home

A study from the National Health and Nutrition Examination Survey demonstrated that individuals who cooked at home and rarely ate take out (0-1 meals per week) consumed 175 fewer calories per day and 343 mg less sodium per day than those that chose to eat at restaurants more often (5-21 times per week)[2].

In addition, the participants that rarely chose take-out saved nearly $170 per month [2]. One of the biggest knocks against healthy eating is that it’s too expensive, but these results prove money can actually be saved as long as fast food is avoided.

Eat Slower To Control Cravings

Today’s lifestyle is fast-paced, busy, and often filled with stress. As a result, people have a tendency to eat quickly and mindlessly. Slowing down while eating can make the meal more enjoyable, but will also reduce cravings later on. Research shows that slowing down and practicing mindfulness while eating led to significant reductions in eating behaviors such as emotional eating, task snacking (eating while doing other activities), and the desire to consume fast food [3].

Research further indicates that eating slowly curbs appetite and decreases hunger [4]. When eating quickly, certain gut hormones aren’t given time to communicate to the brain that the body has eaten an adequate amount. This explains how people that eat extremely fast in eating competitions don’t get full during the race!

Is The No Junk Food Challenge Worthwhile?

Cutting out processed foods in exchange for whole foods will have numerous benefits both physically and mentally. The challenge may only last 3 weeks and results will be seen, but the lessons learned can have an impact that lasts a lifetime. Consider keeping a journal to document progress and keep track of how your relationship with food changes throughout the process.

Reduce Cravings In as Little 3 Weeks

Oftentimes, participants head into the 21 days no junk food challenge with anxiety that they will not be able to control their cravings. However, many people are pleasantly surprised by how much their cravings for junk food reduce in a short amount of time. Part of this can be explained with a little bit of food science.

High fructose corn syrup is a common ingredient found in many processed junk foods. This ingredient has an effect on ghrelin, a hormone produced in the gastrointestinal tract that signals hunger to the brain [5]. Normally, this hormone is suppressed after a meal to let the body know it is full and nourished. However, meals high in fructose have been shown to lessen the suppression of ghrelin, meaning this “hunger hormone” may remain elevated and lead to overeating [6].

Not only are processed foods higher in high fructose corn syrup, but they are typically packed with sodium (salt) for preservation. When salt intake is high, thirst is consequently increased [7]. This can lead to the desire to grab sugary, high-calorie drinks like juice or soda.

Frequently Asked Questions

Common questions about the 3 weeks of no junk food challenge often focus on which foods are allowed and which are prohibited. As a general rule, do your best to stick to foods in their most natural form. Use common sense and remember if it feels like cheating, it probably is!

Is There Healthy Junk Food?

There are certainly prepackaged and partially processed food items that are healthier than others. For example, honey roasted peanuts, beef jerky, and minimally processed energy bars are healthier than candy bars. In most cases, choosing these over cakes and candies would be considered perfectly healthy swaps. However, for the sake of the challenge, anything that falls under the guidelines below is considered junk food [8].

  • Prepackaged
  • Precooked
  • Microwaveable
  • Contains added sugars/artificial sweeteners
  • Contains preservatives (added salt/nitrites)
  • Cured or smoked
  • Fried
  • Contains thickeners, modified starches, colorants, or flavorings
  • Contain high fructose corn syrup
  • Has partially or fully hydrogenated oils (vegetable oil, margarine, shortening oil, canola oil, peanut oil, soybean oil)

What Makes Food Unhealthy Or Junk Food?

To make junk food taste good and last longer, ingredients like sugar, sodium, hydrogenated oils, and other chemicals are added. Over-consuming junk food leads to health consequences such as cardiovascular disease, diabetes, inflammation and obesity [9]. Or in other words, overtime the ingredients will take a toll on your health one way or another.

What Type of Results Can I Expect From The 21 Day No Junk Food Challenge?

While the challenge is short, sticking to it will provide noticeable changes. Eliminating junk food should lower caloric intake and lead to respectable weight loss. By replacing unhealthy foods with whole foods, the body receives more vitamins and fiber which can lead to improved immune function and better digestion [10].

Many participants find that their energy levels increase by cutting out junk food and this motivates them to continue with their newfound healthy eating habits. In addition, some even learn some ways get rid of their banana fat rolls after reducing junk food.

Therefore, the challenge demonstrates how even brief removal of junk food from the diet can benefit the body.

Develop Healthy Eating Habits With 21 Days Of No Junk Food

Keep in mind that your body’s current health condition, whether good or bad, is a result of several years of decisions and habits. It’s unrealistic to expect everything to be reversed in less than a month’s time, but you can surely still see great results in just three weeks.

Committing to the 3 weeks no junk food challenge is a short-term lifestyle change that can lead to long-term benefits. While the immediate outcomes are great to measure, the lifestyle changes that occur long after the challenge has ended make it even more worthwhile. If you’re up to the challenge, take the first step towards transforming your eating habits with the no junk food challenge and see how long you can keep it up.


[1] Dominic Wu, M. D. (2017, March 24). Eating better: 3 keys to healthy grocery shopping. Harvard Health. Retrieved February 5, 2022, from https://www.health.harvard.edu/blog/eating-better-3-keys-to-shopping-healthfully-at-the-grocery-store-2017032411333

[2] Reid, N., Rutkow, L., Gudzune, K., Padula, W., Thorpe, R., McGinty, E. (2020). PMU39 cooking at home can save money, regardless of food price: A multilevel analysis of meals prepared away from the home on diet measures and food expenditures. Value in Health, 23. https://doi.org/10.1016/j.jval.2020.04.813

[3] Hanson, P., Shuttlewood, E., Halder, L., Shah, N., Lam, F. T., Menon, V., Barber, T. M. (2018). Application of mindfulness in a tier 3 obesity service improves eating behavior and facilitates successful weight loss. The Journal of Clinical Endocrinology Metabolism, 104(3), 793–800. https://doi.org/10.1210/jc.2018-00578

[4] Angelopoulos, T., Kokkinos, A., Liaskos, C., Tentolouris, N., Alexiadou, K., Miras, A. D., Mourouzis, I., Perrea, D., Pantos, C., Katsilambros, N., Bloom, S. R., le Roux, C. W. (2014). The effect of slow spaced eating on hunger and satiety in overweight and obese patients with type 2 diabetes mellitus. BMJ Open Diabetes Research Care, 2(1). https://doi.org/10.1136/bmjdrc-2013-000013

[5] Pradhan, G., Samson, S. L., Sun, Y. (2013, November). Ghrelin: Much more than a hunger hormone. Current opinion in clinical nutrition and metabolic care. Retrieved February 5, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049314/

[6] Teff, K. L., Elliott, S. S., Tschöp Matthias, Kieffer, T. J., Rader, D., Heiman, M., Townsend, R. R., Keim, N. L., D’Alessio, D., Havel, P. J. (2004). Dietary fructose reduces circulating insulin and leptin, attenuates postprandial suppression of ghrelin, and increases triglycerides in women. The Journal of Clinical Endocrinology Metabolism, 89(6), 2963–2972. https://doi.org/10.1210/jc.2003-031855

[7] Hebebrand, J., Albayrak, Ö., Adan, R., Antel, J., Dieguez, C., de Jong, J., Leng, G., Menzies, J., Mercer, J. G., Murphy, M., van der Plasse, G., Dickson, S. L. (2014). “eating addiction”, rather than “Food addiction”, better captures addictive-like eating behavior. Neuroscience Biobehavioral Reviews, 47, 295–306. https://doi.org/10.1016/j.neubiorev.2014.08.016

[8] FAQs for consumers – home | Agricultural Marketing Service. (n.d.). Retrieved February 5, 2022, from https://www.ams.usda.gov/sites/default/files/media/FAQs%20for%20Consumers%20-%20English.pdf

[9] Marti, A. (2019, August 15). Ultra-processed foods are not “real food” but really affect your health. Nutrients. Retrieved February 5, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723973/

[10] Melse-Boonstra, A. (2020, July 24). Bioavailability of micronutrients from nutrient-dense whole foods: Zooming in on dairy, vegetables, and fruits. Frontiers in nutrition. Retrieved February 5, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7393990/

About the Author

Nathan Petitpas

Nathan has been a fitness enthusiast for the past 12 years and jumps between several types of training such as bodybuilding, powerlifting, cycling, gymnastics, and backcountry hiking. Due to the varying caloric needs of numerous sports, he has cycled between all types of diets and currently eats a whole food diet. In addition, Nathan lives with several injuries such as hip impingement, spondylolisthesis, and scoliosis, so he underwent self-rehabilitation and no longer lives with debilitating pain.