Skip to main content

How to Lose 20 Pounds Eating an Oatmeal Diet

Ted is a self-avowed gym rat. He has a Master's degree in Counseling and is both a photographer and published author.

The fiber in oatmeal keeps you feeling full and improves digestion, helping you lose 2-4 pounds a week.

The fiber in oatmeal keeps you feeling full and improves digestion, helping you lose 2-4 pounds a week.

What Is the Oatmeal Diet?

Oatmeal is an extraordinary, whole-grain food that is rich in fiber, antioxidants, and selenium. This versatile grain can be used in a wide variety of dishes—not just breakfast!—to add fiber to your diet to help you lose weight.

The idea behind the oatmeal diet is to eat oatmeal as your main course for one or two meals every day. Incorporating this grain, in either rolled or steel-cut form, into the majority of your meals will help you feel fuller longer, reducing the number of calories you consume without leaving you feeling deprived.

The basic diet goes like this:

  • Oatmeal for breakfast.
  • A healthy, balanced lunch.
  • Oatmeal as a before-dinner snack.
  • A sensible, moderate dinner.
  • Oatmeal for dessert
  • Plenty of water.
  • Exercise.
  • Plenty of sleep.

How Much Weight Can I Expect to Lose on the Oatmeal Diet?

By sticking to an oatmeal diet, you can expect to lose 2-4 pounds a week. This means that in approximately two months, you can lose as much as 20 pounds.

Breakfast on the Oatmeal Diet

This step should come naturally to most of us. While on the oatmeal diet, your breakfast is . . . oatmeal!

Every morning, eat a bowl of oatmeal (see ideas for spices and other things to add below). A cup of oatmeal contains approximately 140 calories and four grams of fiber. Fiber doesn't just fill your stomach, it can help you eat fewer calories. Fiber facilitates digestion, which helps your body get rid of what it doesn't need. Fiber can also lower your risk of cardiovascular disease and diabetes.

Spice, fruit, and tasty milks can make oatmeal a delicious meal any time of day.

Spice, fruit, and tasty milks can make oatmeal a delicious meal any time of day.

What to Put on Top of Your Oatmeal

Greek yogurt

Chopped almonds or walnuts


Sliced bananas

Unsweetened berries

Raisins or other dried fruit

Sliced apples


Almond or peanut butter

How Much Oatmeal Is a "Serving"?

1/2 cup of dry rolled or steel-cut oats cooked in 1 cup of water will yield about 1 cup of oatmeal. That's a serving!

Oatmeal With Almond Milk and Apples

  • 1 cup old-fashioned or steel-cut oatmeal
  • 2 cups almond milk
  • 1 apple cut into bite-sized pieces)
  • 2 teaspoons cinnamon
  • 1 cup unsweetened applesauce

In a medium saucepan, combine the almond milk, oatmeal, and cinnamon. Keep the heat on low until most of the milk is absorbed (stir as needed). Once most of the milk is absorbed, add the applesauce and stir. If you like your apples soft, add them in now. If you like some crunch, wait until you are about to serve. Once all the applesauce is absorbed, remove from heat and serve. Total cooking time is about 15-20 minutes.

Lunch on the Oatmeal Diet

For lunch, eat lean proteins, vegetables (preferably raw), and low-sugar fruits. Avoid bread and pasta, as you are getting plenty of good carbohydrates from the oatmeal.

Here are some ideas:

Scroll to Continue
  • Spinach salad with tomatoes, cucumbers, and a scoop of tuna salad.
  • Hardboiled eggs with wholewheat toast and raw veggies.
  • Vegetable or chicken soup with rice or corn crackers
  • Quiche or frittata with vegetables and goat cheese

How Will Oatmeal Help Me Lose Weight?

Whole-grain oatmeal has only been minimally processed and still has its three major parts intact: the germ, the bran, and the endosperm. This means that it retains all of its nutrients, including B vitamins and fiber, which are stripped away when grains are refined.

Whole grains are considered "complex" carbohydrates. These types of carbs have a more complex chemical structure and take longer to break down. This makes them "good" carbs because when your body has to work harder to break down your food, your metabolism gets a boost, which helps to maximize your body's ability to burn fat.

Oats are also rich in beta-glucan, a soluble fiber that helps fight insulin resistance, hypertension, and abnormal fat levels in the blood. A 2013 study found that eating oats reduces body fat, specifically abdominal fat, and improves lipid profiles and liver functions.

High-fiber carbohydrates like oats also help prevent heart disease and colorectal cancer and help to lower blood pressure.

Which Type of Oatmeal Should I Eat?

Avoid "instant" oats, as they are lower in fiber, and pre-sweetened oatmeal, which is high in sugar. Choose rolled or steel-cut oats, which are minimally processed. Rolled and steel-cut oats are denser and will keep you feeling full longer. Consider these half-cup serving (uncooked, without milk) nutrition facts:

  • Both types contain 74 calories (per 1/2-cup serving,) 3 grams of protein, and 2 of grams fiber. Steel-cut oats and quick oats are high in vitamins E, B-1 and B-2.
  • Instant oatmeal cereals usually contain large amounts of sugar and sodium.

How Much Weight Can I Expect to Lose?

Stick with the oatmeal diet and you can lose 2-4 pounds a week. In about two months, you can lose as much as 20 pounds.

Oatmeal Snack Ideas

  • Add oatmeal to a fruit or vegetable smoothie to give your snack some heft.
  • Low-sugar oatmeal cookies with nuts and dried fruit make a great snack.
  • Oat snack bars (low-sugar) are satisfying and filling.
  • Make an oatmeal "pudding" by cooking oats in the usual way with fruit, nuts, and even cocoa powder. When it comes to a boil, put a lid on the pot and let the mixture sit for 20 minutes until it is set like pudding.

Dinner on the Oatmeal Diet

Prepare a simple, high-protein dinner with lots of vegetables (raw and cooked).

  • Grill some chicken and prepare a satisfying, crunchy salad.
  • Grill or pan-fry some fish (salmon is a great choice) and eat with steamed vegetables.
  • Prepare a small, lean steak.
  • A turkey burger is a great choice. Serve with zucchini "fries."
  • Consider preparing a savory oatmeal dish for dinner, but be sure to add lots of vegetables and protein.
Steel-cut oats have a chewy texture like buckwheat and make a nice change from rolled oats.

Steel-cut oats have a chewy texture like buckwheat and make a nice change from rolled oats.

Savory Oatmeal With Squash and Spinach

Oats are just as good-tasting and good for you when they're treated like rice or couscous. Try cooking them with broth to boost the protein and create a rich, savory flavor. Combine vegetables, herbs, and even eggs or meat for a delicious oatmeal dish that's right any time of day.


  • 1 cup water or broth
  • 1/2 cup rolled oats
  • 1/4 cup chopped fresh spinach
  • 1/4 cup cubed roasted butternut squash or sweet potato
  • 1 teaspoon rosemary, (or other spice of choice)
  • 1 fried egg, (optional)
  • salt and pepper, to taste


  1. Combine water or broth and oats in a small saucepan. Boil over high heat, stirring occasionally, until thickened, about 15-20 minutes.
  2. Stir in spinach and remove from heat.
  3. Add squash, spice, salt, and pepper. Top with egg, if desired.
  4. Serve warm.

Can I Eat Oats as Part of a Low-Carb Diet?

If you are trying to avoid carbs, the oatmeal diet isn't for you. Oats do contain carbs (27g per 1/2 cup, uncooked, or 23g net carbs), but it's worth noting that they are also rich in beta-glucan, which helps slow digestion and reduces appetite. So, for a carbohydrate oats are among the best.

The oatmeal diet certainly isn't a no-carb diet, but when paired with protein, vegetables, and low-sugar fruits, it can still be a low-carb plan for those trying to limit carbohydrate intake.

Be adventurous! Try this combination of balsamic vinegar, strawberries, and oats for a tangy, healthy meal.

Be adventurous! Try this combination of balsamic vinegar, strawberries, and oats for a tangy, healthy meal.

Tangy and Creamy Strawberry Oatmeal


  • 1 cup water
  • 1/2 cup old-fashioned oats
  • 1 teaspoon ground cinnamon (you can also toss a cinnamon stick in w/ the boiling water+
  • 1/2 cup chopped strawberries (fresh or frozen & defrosted)
  • 1 teaspoon balsamic vinegar
  • 2 tablespoons Greek yogurt
  • 1/2 teaspoon real vanilla extract


In a small pot, combine water, oatmeal, and cinnamon. Cover and bring to a boil. Reduce heat to low. While the oatmeal absorbs the water, combine the strawberries and balsamic vinegar in a small bowl. Smash with the back of a fork and mix until you have strawberry mush. Add the yogurt and vanilla and mix well.

Once the water and oatmeal are absorbed, add the strawberry mixture and stir until combined. Let thicken for a minute or so, remove from heat, and serve.

Almond milk adds a little protein to your oatmeal and is a great option for those who don't digest dairy well.

Almond milk adds a little protein to your oatmeal and is a great option for those who don't digest dairy well.

Types of Milk to Pair With Oatmeal

Almond, low-fat, skim, soy, hemp, and coconut.

Steel-cut oats with bananas and almond butter.

Steel-cut oats with bananas and almond butter.

Oatmeal With Banana and Almond Butter


  • 1 cup unsweetened almond milk
  • 1/2 cup steel-cut oats
  • 1/2 banana, thinly sliced
  • 1 tablespoon almond butter


In a medium saucepan, combine the almond milk and oatmeal. Keep the heat on low until most of the liquid is absorbed. Add in half of the banana slices and all of the almond butter. Mix together and let the oatmeal soak up the rest of the milk. Remove from the heat and top with the remaining banana slices.

Oatmeal Cookies for Dessert and Snacking

Ingredients for oatmeal ginger cookies.

Ingredients for oatmeal ginger cookies.

Oatmeal Ginger Cookies


  • 2 bananas
  • 1/2 cup molasses
  • 2 tsp vanilla
  • 1 cup all-purpose flour
  • 2 cups rolled oats
  • 2 tsp baking soda
  • 1 tsp ginger
  • 1/2 tbsp cinnamon


Preheat oven to 350 F. Mash bananas and combine with molasses and vanilla. Mix together dry ingredients, add banana mixture, and stir in rolled oats. Form teaspoon-sized balls and place on greased (or sprayed) baking sheet. Bake 10-15 minutes.

Oatmeal ginger cookies with bananas and molasses.

Oatmeal ginger cookies with bananas and molasses.

Here is another great recipe for low-fat oatmeal cookies. Make up a batch and store them in an airtight container. Make extra batches to store in the freezer. Carry a serving of these healthy treats to work and enjoy them instead of vending machine snacks.

Having snacks prepared and portioned in advance helps you maintain control of your daily caloric intake, based on your age, height, and activity level.

Other Tips to Make the Oatmeal Diet Work

  • Engage in 30 minutes of exercise, five days a week. Eating oatmeal provides ample energy for exercise, which should be at the core of your weight loss program. Enjoy activities such as brisk walking, cycling, or swimming, and carry a portion of your low-fat oatmeal cookies for a healthy after-workout snack. You can burn up to 150 calories by walking briskly for 30 minutes. In addition, your metabolism continues to burn calories faster after exercising, even when at rest.
  • Be sure to drink plenty of water to maintain hydration and energy levels.
  • Get plenty of sleep. When the body has enough rest, the metabolism performs more efficiently, helping with weight-loss.

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2011 tedcampbell2792


Rebecca on August 20, 2018:

Yes, this is a fad diet so you have to learn to eat a healthy and maintainable diet when you decide to stop. Once you have lost the desired weight you should consider visiting a nutritionist/dietitian for nutrition advice to keep the weight off.

I am a poor uni student and can confirm that eating oatmeal multiple times a day has done wonders for me! I am a huge snacker but eating oatmeal for breakfast and lunch helps me to keep full and stop snacking. Oats are also sooo cheap! One thing you have to be careful about is the toppings that you add. The toppings can often easily add 200 calories that you dont need :) I usually have mine plain or with 1/2 a banana on top

Dudemycar on June 11, 2018:

This is a fad diet. Effective with the only draw back is what to do after the target weight is achieved.

Oats and honey would be a great combination. Honey for blood sugar levels while oats act to level the blood sugar.

Still. Calories in vs calories out. Got to workout.

pretty on January 29, 2018:

Usually I let it in water for the night, & drink it early in the morning.

what are the benefits.!!

PaulWShep on January 18, 2018:

I like this idea & it’s cheap too!! Dinner will be a big salad & tuna or chicken to keep up the vits & minerals! I’m on Thyroid treatment and my metabolism has dropped, so it’s worth a try!!

beowulf on November 21, 2017:

This is very helpful thanks.

CHRIS on December 01, 2016:

Kay has it all figured out . She plans to go back to eating " regular healthy food ".

There's always an idiot .

Probably a Trump voter ,

Raïza on November 05, 2016:

Good advice

Zangmo on October 15, 2016:

I ll try frm 2day

Royal on October 08, 2016:

I am going to start this amazing diet

sopha on July 31, 2016:

i will try and let u know

Kay on April 07, 2016:

I love oatmeal. I am willing to try this. But when I start to eat regular healthy food, will I not gain it all back?

Zina on January 05, 2016:

I will try this

margo on June 25, 2015:

I will try it.

Vkthbjm on November 11, 2013:


AngelaKaelin from New York on March 06, 2011:

Excellent info.! Oatmeal is great right before a morning work out! Gives a great energy burst and it's cleansing!

stars439 from Louisiana, The Magnolia and Pelican State. on March 02, 2011:

Thank you. I am going to try this. I like oat meal. I will definitely start trying it in the morning, every morning. GBY

Tess45 from South Carolina on February 20, 2011:

I do like oatmeal....and being 20 lbs lighter would be nice too. Any plan that lets me eat cookies, sounds good to me!

nicomp really from Ohio, USA on February 17, 2011:


Related Articles