The 3-Day Diet

What Is the 3-Day Diet?

The 3-Day Diet, also called the Military Diet, is a fad diet that claims that by drastically cutting calories for three days, you can drop 10 pounds in a week. It also encourages you to lower the amount of calories you eat for four more days after the initial three-day plan.

Despite the name, it didn't come from the military. The name was inspired by the discipline and willpower you need to be in the military, implying that you need the same traits to complete this diet.

How Do I Start the 3-Day Diet?

First, you'll want to get your grocery list together. Organize the foods by type to make shopping easy. You'll also want to prepare for the changes that come with eating less than you're used to. You may not have as much energy, so you might need to scale back on your responsibilities and plans for exercise. 

It may be helpful to write out your meals for each day, too, or prep them ahead of time, mixing and matching the suggested foods to your liking for each meal. This can help you stay on track on busier days and ensures your food is already portioned out whenever you get hungry for your next meal.

3-Day Diet Foods

Because the 3-Day Diet is very specific about approved foods, it's easy to know what's allowed and what isn't. There is a list of substitutions if you don’t like a certain food, and there's also a vegetarian and vegan version of the diet. 

If you do make substitutions, rather than matching serving sizes, make sure that you adjust the portion sizes so that you get the same amount of calories. One cup of a certain food may have more or less calories than one cup of a different food. The 3-Day Diet has a serving size guide to help you with this.

Foods allowed on the 3-Day Diet

Some common foods you can eat on the standard Military Diet include:

• Toast and saltine crackers
• Fruit such as grapefruit, bananas, and apples
• Proteins such as tuna, boiled eggs, peanut butter, and hot dogs
• Select vegetables, including broccoli, green beans, and carrots
• Dairy like ice cream, cottage cheese, and cheddar cheese
• Tea and coffee
• No-calorie seasonings such as salt, pepper, lemon juice, fresh garlic, and certain spices
• Low-calorie condiments such as mustard, hot sauce, and low-sodium soy sauce

The vegan and vegetarian version of the diet replace milk-based items with dairy-free options. It also includes meat alternatives like beans, tofu, hummus, and veggie hot dogs.

Foods to avoid on the 3-Day Diet

This diet largely focuses on what you can eat. Anything else shouldn't be included in your three-day plan. The guidelines do mention a few things that you should avoid for sure, such as:

• Cream and sugar in your coffee
• Sweeteners except stevia
• Garlic salt
• Alcohol
• Condiments such as mayo, ketchup, and store-bought salad dressings

3-Day Diet food list

To help you with grocery shopping or meal prep, here are all the ingredients you need for the Military Diet sorted by food type.

Produce

• 2 bananas
• 2 apples
• 1 grapefruit
• Green beans (fresh, frozen, or canned)
• 1 small head of broccoli
• Carrots

Meat and seafood

• 3 cans of tuna
• Hot dogs
• 3 ounces of your choice of meat

Dairy

• Cottage cheese
• Cheddar cheese
• Vanilla ice cream
• Eggs

Bakery

• Whole wheat bread

Snacks

• Saltine crackers

Condiments

• Peanut butter

Beverages

• Tea and coffee

Pros and Cons of the 3-Day Diet

Every diet has its pros and cons, and some may work better for your lifestyle and preferences than others. The 3-Day Diet may not be for everyone, so it's important to know some of the main benefits and drawbacks.

Benefits of the 3-Day Diet

Even though the diet is very short, it does have some pros other than weight loss. Its rules encourage a few helpful things:

• No added sugars and sweeteners that don't have nutritional value, except for stevia
• Cooking your own food instead of eating out
• An easy-to-follow meal plan

Risks of the 3-Day Diet

The diet's main weaknesses come from the effects of drastically cutting calories. This can have short- and long-term consequences.

You're not burning fat. Generally, the goal of weight loss is to lose fat, which takes time. When you lose weight on a three-day diet, you're likely just losing water weight. So, one con of the Military Diet is that you're not actually reaching the typical health goal of losing weight through fat loss.

It limits exercise. While the 3-Day Diet technically advises moderate exercise, such as walking, it also suggests cutting back if you feel dizzy or weak due to a lack of energy during the diet. Exercise is key to proper weight loss that targets fat instead of muscle mass. But the calorie limit of the Military Diet restricts how active you can be because your body simply cannot sustain the exercise.

It can disrupt normal body functions. Cutting back on nutrients can lead to constipation, exhaustion, low energy, hair loss, loss of bone strength and density, and a weakened immune system.

It can affect your mental health. Fad diets like this one that promise quick, short-term weight loss through extreme changes can take a toll on your body. It often leads to a cycle of yo-yo dieting, where you may start strong but "give in" to cravings later, breaking the diet rules. This can make you feel guilty before you restart. This can increase your chances of eating disorders and low quality of life and well-being.

Does it allow for restrictions or preferences?

There is a vegan and vegetarian version of the diet, as well as a substitution list if you prefer other foods than the original suggestions. The substitution list also includes gluten-free choices and serving sizes for the alternatives.

Who shouldn't try the 3-Day Diet

This diet is only safe short-term. But if you struggle to set healthy eating habits already, you may want to avoid it. Studies show that dramatically cutting calories can encourage an unhealthy relationship with food as well as eating disorders.

Rapid weight-loss diets are also generally not suggested for:

• Children
• Teenagers
• Pregnant women
• Older adults

3-Day Diet Review: What Our Expert Says

Dr. Melinda Ratini is a physician specializing in family medicine. She has expertise in treating obesity, coronary artery disease, hypertension, among other conditions. Here is her take on the 3-Day Diet:

Does it work?

You will likely lose weight on any diet if you eat less than 910 calories a day. But losing 10 pounds in three days is both unlikely and unhealthy. To lose just 1 pound of body fat, you need to reduce your daily calories by about 500 a day for a whole week. That's giving up 3,500 calories over the course of seven days. To lose 10 pounds in three days would mean decreasing your calorie intake by 35,000 calories in just three days! The Academy of Nutrition and Dietetics recommends a slow and steady weight loss of no more than 1/2 to 1 pound a week. Otherwise you are losing muscle and water, as well as weakening your bones. You also are much more likely to gain it all back.

Is it good for certain conditions?

The 3-Day Diet is low calorie, but it certainly is not low-fat, low-salt, or low cholesterol, so it is not a healthy option for most people with certain medical conditions such as diabetes, hypertension, heart disease, and high cholesterol. If you are overweight, weight loss is key to managing these conditions. But it should be a healthy and sustainable weight loss that includes healthy nutrition and exercise.

The final word

The 3-Day Diet is a very low-calorie diet that uses simple foods that are low in cost and easy to find and prepare. A short-term weight loss is likely. But that is where the good news ends.

During the three days of the diet, balanced nutrition is lacking. Some of the foods that are recommended are high in salt and fat and would not be appropriate for people with certain medical problems likeheart disease, high blood pressure, diabetes, or high cholesterol. You may not be getting enough vitamins, minerals, and fiber while you are on the diet. If you are taking medicine for your diabetes and want to try the 3-day diet, it's important to talk with your doctor first about how to adjust your medicine.

Physical activity is an important part of a healthy lifestyle and helps prevent and treat heart disease and diabetes. But the 3-Day Diet does not address this at all. Nor does it teach you how to make changes in your diet that will allow for a lifetime of healthy eating.

Finally, such a restrictive diet takes the enjoyment out of eating. During the three days a week that you are following the plan, eating out or with others could be very tough. Also, boring diets are very hard to maintain. The temptation to overeat on the other four days of the week when you are not dieting will likely be high.

Remember, when it comes to weight loss, slow and steady really does win the race.

3-Day Diet Menu

The Military Diet has a proposed menu that outlines what you should eat for each meal every day. You can eat the foods whenever you want, and you can rearrange the order to your liking. The main rule is that you don't eat anything that's not listed on the diet's plan.

Standard Military Diet Menu

The regular menu outlined by the 3-Day Diet is broken up by day and meal.

Day 1

Breakfast

• 1/2 grapefruit
• 1 slice of toast
• 2 tablespoons of peanut butter
• 1 cup caffeinated coffee or tea

Lunch

• 1/2 cup of tuna
• 1 slice of toast
• 1 cup caffeinated coffee or tea

Dinner

• 3 ounces of any type of meat
• 1 cup of green beans
• 1/2 banana
• 1 small apple
• 1 cup of vanilla ice cream

Day 2

Breakfast

• 1 egg
• 1 slice of toast
• 1/2 banana

Lunch

• 1 cup of cottage cheese
• 1 hard-boiled egg
• 5 saltine crackers

Dinner

• 2 hot dogs (without bun)
• 1 cup of broccoli
• 1/2 cup of carrots
• 1/2 banana
• 1/2 cup of vanilla ice cream

Day 3

Breakfast

• 5 saltine crackers
• 1 slice of cheddar cheese
• 1 small apple

Lunch

• 1 hard-boiled egg (or cooked however you like)
• 1 slice of toast

Dinner

• 1 cup of tuna
• 1/2 banana
• 1 cup of vanilla ice cream

Vegan and vegetarian Military Diet menu

This version also has a proposed menu with substitutions for animal products.

Day 1

Breakfast

• 1/2 grapefruit
• 1 slice of toast
• 2 tablespoons of peanut butter
• 1 cup caffeinated coffee or tea

Lunch

• 1/2 an avocado
• 2 tablespoons of hummus
• 1 slice of whole wheat toast
• 1 cup caffeinated coffee or tea

Dinner

• Tofu (prepared any style but not more than 300 calories)
• 1 cup of green beans
• 1/2 banana
• 1 small apple
• 1 cup of vanilla ice cream (dairy-free ice cream for vegans)

Day 2 

Breakfast

• 1/2 cup baked beans
• 1 slice of whole wheat toast
• 1/2 banana

Lunch

• 1 cup unsweetened soy, hemp, or almond milk
• 1/2 avocado
• 2 tablespoons hummus
• 5 saltine crackers

Dinner

• 2 veggie hot dogs (without bun)
• 1 cup of broccoli
• 1/2 cup of carrots
• 1/2 banana
• 1/2 cup of vanilla ice cream (dairy-free ice cream for vegans)

Day 3 

Breakfast

• 1 slice cheddar cheese (About 15-20 almonds for vegans)
• 5 saltine crackers (1/2 cup couscous or quinoa)
• 1 small apple

Lunch

• 1/2 avocado and 1 tablespoon hummus
• 1 slice whole wheat bread

Dinner

• 1/2 cup canned chickpeas
• 1/2 banana
• 1 cup of vanilla ice cream (Dairy-free ice cream for vegans)