Oatmeal Diet

 By Mizpah Matus B.Hlth.Sc(Hons)

oatmeal-dietThe basic Oatmeal Diet involves replacing one or two meals a day with oatmeal.

This is good since oatmeal has a number of health benefits including

  • healthy weight management
  • reducing cholesterol
  • and potentially lowering the risk of certain types of cancer.

Some have taken this further by eating nothing but oatmeal. This approach is a tad extreme, but most people follow the version listed below.

Oatmeal Diet Basics

One method of doing the oatmeal diet involves varying the amount of oatmeal eaten over three phases.

Phase One

  • Dieters eat nothing but oatmeal for the first week.
  • You can eat ½ cup of oatmeal for each meal, which may be combined with ½ cup of skim milk if desired.
  • Only whole oatmeal is allowed.
  • Instant oatmeal and granola bars should be avoided for the first seven days.
  • Calorie consumption for the first seven days should be between 900-1200 calories per day.

Phase Two

  • For the next 30 days dieters continue having ½ cup of oatmeal three times a day in addition to their regular diet.
  • Instant oatmeal is now permitted.
  • Calories may now be increased slightly to 1000-1300 per day.
  • A morning snack of ½ cup of fruit and an afternoon snack of ½ cup raw vegetables are allowed.

Phase Three

  • After 30 days you may begin to eat your normal diet while continuing with one meal and one snack of oatmeal daily.
  • Dieters are advised to limit their intake of fats when returning to normal eating.

The biggest challenge to eating oatmeal (also known as porridge in the UK) is how to keep adding things to prevent monotony and blandness. See some ideas here.

Oatmeal Diet Alternatives

  1. Medifast– Uses meal replacements like oatmeal and shakes to promote weight loss.
  2. Special K Diet– Replaces 2 meals a day with Special K Cereal.
  3. Cooking with Oats: Oat Bran, Oatmeal, and More

Recommended Foods

Oatmeal, skim milk, berries, bananas, apples, oranges, grapes, carrots, red pepper, celery, lettuce, spinach, chicken breast, fish, coffee, tea, club soda, sugar free pudding.

Sample 1 Day Meal Plan

4 more days of the oatmeal diet meal plan can be found here.


½ cup oatmeal
½ cup skim milk
1 tablespoon raisins
½ teaspoon cinnamon
coffee or tea

Morning Snack

½ cup blueberries

Lunch½ cup oatmeal
1/2 cup low fat yogurt
1 banana
Afternoon Snack

½ cup raw vegetable sticks


4 oz grilled chicken breast
Large green salad
½ cup oatmeal

Evening Snack

Sugar free pudding

Exercise Recommendations

30 minutes of exercise is recommended on 3-5 days of the week.

Costs and Expenses

The only cost for this diet is for groceries, which will probably be even less than usual because oatmeal is very inexpensive.


  • Oatmeal is high in soluble fiber, which helps to promote a feeling of fullness after meals.
  • A diet high in oatmeal can reduce the ‘bad’ LDL cholesterol without affecting the ‘good’ HDL cholesterol and has been demonstrated to be as effective as cholesterol lowering medication.
  • Oatmeal is a good source of low glycemic carbohydrates and can help to promote stable blood sugar levels.
  • Oats contain phytonutrients called lignans, which are beneficial for heart health.
  • Oats are very inexpensive.


  • Calorie intakes are below that recommended for safe and healthy weight loss.
  • Lack of variety in the diet will limit the ability to obtain adequate nutrition.
  • Diet involves a dramatic change in normal eating patterns, especially for the first week, which has the potential to trigger yo-yo dieting for some people.

The First 7 Days May be Difficult

Any diet that is based on a single food while excluding other healthy foods can be regarded as a fad diet that will not be supportive of the health of the dieter. It is not recommended to follow the first seven days of the version of the diet where oatmeal is the only food permitted.

However, the oatmeal diet is based on a nutritious food that can help to reduce appetite, which makes it a good source of carbohydrates for a weight loss diet. If weight loss is to be maintained over the long term it will also be necessary to pay attention to other aspects of nutrition and lifestyle.


  • Van Horn, L., Emidy, L. A., Liu, K., Liao, Y., Ballew, C., King, J., & Stamler, J. (1988). Serum lipid response to a fat-modified, oatmeal-enhanced diet. Preventive medicine, 17(3), 377-386. Link
  • Lammert, A., Kratzsch, J., Selhorst, J., Humpert, P. M., Bierhaus, A., Birck, R., … & Hammes, H. P. (2008). Clinical benefit of a short term dietary oatmeal intervention in patients with type 2 diabetes and severe insulin resistance: a pilot study. Experimental and clinical endocrinology & diabetes, 116(02), 132-134. Link
  • Katan, M. B. (2009). Weight-loss diets for the prevention and treatment of obesity. New England Journal of Medicine, 360(9), 923-925. Link
 By Mizpah Matus B.Hlth.Sc(Hons)
Last Reviewed: June 10, 2015. Disclaimer
Free Newsletter

Don't miss out on the latest diets!

Join now - it's free.