Topics » How To » New to an Oil-Free Diet? Here’s What You Need to Know
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Mainstream nutrition information offers conflicting views on the effects of dietary oils. With outlets like Harvard Health advising the use of oils high in polyunsaturated fatty acids (PUFAs) instead of saturated[1] and numerous claims and studies citing olive oil’s purported ability to lower heart disease risk,[2] it may seem unusual or even extreme to recommend eliminating all oils as part of a healthy eating pattern.

But that’s exactly what you do on a whole food, plant-based diet. Along with animal products and processed foods, extracted oils are left off the plant-based plate in favor of whole, nutritious fat sources.

Does Oil Have Nutritional Value?

When compared to the foods included in a whole food, plant-based diet, oil has a significantly higher caloric density per pound.[3]

  • Vegetables: 100 calories
  • Fruit: 300 calories
  • Nuts: 2,500 to 3,000 calories
  • Oil: 4,000 calories

A typical one-tablespoon serving of oil contains between 120 and 130 calories, all of which come from fat. Aside from omega-3 and omega-6 fatty acids, few nutrients are present except for small amounts of vitamin E and vitamin K. Coconut oil is particularly high in saturated fat, about 90% of the total fat content, which is higher than the 40% saturated fat found in lard.[4] Oil quality is also difficult to determine, as the fats in many plant oils may become damaged if exposed to heat during processing, packing, transportation, storage, or cooking.

What Happens to Your Body When You Eat Oil?

High-fat foods, including oils, elicit an intense reaction from your body and brain, which can contribute to their apparent addictive qualities.[5] You may get an initial feeling of pleasure when eating oily foods, but what follows is far from good for your body. After a high-fat meal:

  • Endothelial function diminishes for several hours, leading to decreased blood flow[6]
  • Digestion slows as enzymes, stomach acid, bile, and other juices work to break down the fats
  • Excess fats are converted into triglycerides and cholesterol in the liver and stored in the body as a future source of fuel

Consuming oil also has a negative effect on gut bacteria. Saturated fats appear to have the greatest impact on the number, richness, and diversity of bacteria in the gut microbiome[7] which may be associated with reduced production of beneficial short-chain fatty acids and can lead to an increase in inflammation and free radical production. This may result in DNA damage and deplete your body’s stores of antioxidants as your system tries to combat the onslaught.[8]

Thoughts on “Healthy” Oils

What about information showing some oils have health benefits? Much of it appears to be comparative. Oils containing more anti-inflammatory omega-3 fatty acids may be less damaging than those with a lot of pro-inflammatory omega-6 fats, high saturated fat content, or trans fats, but some data shows all oils impair endothelial function to various degrees.[9]

This is true even of cold-pressed oils. Purported health benefits of these oils may be due to the lack of heat or chemicals used in processing.[10] The expeller pressing process creates heat from friction, and other oils are extracted using solvents, residues of which may appear in trace amounts in the final product.[11] Because unsaturated fats become unstable at high temperatures, oils exposed to heat could have more free radicals and, thus, cause greater cellular damage when ingested.

Getting Healthy Fats from Whole Food Sources

You do need some fat in your diet to help absorb fat-soluble nutrients and maintain cellular health, but it’s not nearly as much as most people are consuming. As of 2007, the average American over age 2 was taking in around 79 grams of fat per day, which equates to 35.6% of calories from fat on a 2,000-calorie diet.[12] The whole food, plant-based lifestyle keeps fat intake between 10% and 15%; some recommendations suggest higher amounts may be safe when consuming mostly unsaturated fats.[13] Total fat needs may differ depending on age, activity level, and health status.

Here are some tasty ways to get healthy plant-based fats without added oil[14]:

  • Nuts, seeds, and their butters (look for brands with no added oil, sugar, or salt)
  • Avocados
  • Beans like chickpeas and pinto beans
  • Whole or fermented soy products

Cooking Without Oil: Quick Tips

It’s easy to adapt your favorite recipes and cooking methods to an oil-free lifestyle. Try these simple tips to remove oil without losing flavor:

  • Roast vegetables at lower temperatures for a longer time[15]
  • Mist vegetables with low-sodium vegetable broth or apple cider vinegar and your favorite seasonings prior to roasting[16]
  • Steam vegetables before seasoning as desired
  • Use silicone mats, pans, or molds for roasting and baking
  • Saute with small amounts of water, vegetable broth, or naturally flavored vinegar
  • Heat pans to higher temperatures for stir frying
  • Invest in an air fryer for “fries” and “chips”
  • Replace oil in baked goods[17] with applesauce, nut butters, pumpkin puree, aquafaba,[18] or plant-based yogurt

Experiment until you find your favorite methods, and you won’t miss the greasy, heavy feeling of oil at all. Your heart, gut, and taste buds will thank you for it.


  1. McManus, Katherine D. “10 Foods That May Impact Your Risk of Dying from Heart Disease, Stroke, and Type 2 Diabetes.” Harvard Health Blog. October 7, 2019.
  2. Mornin, Karen. “These Foods Will Lower Your Risk of Heart Disease.” The Conversation. November 5, 2017.
  3. “Calorie Counts Comparison.” Healthy Diet Habits.
  4. Shute, Nancy. “Lard Is Back in The Larder, but Hold the Health Claims.” NPR. May 2, 2012.
  5. Todd, Carolyn L. “Here’s What Actually Happens in Your Body When You Eat Fat.” Self. June 4, 2019.
  6. “Oils.”
  7. Prados, Andreu. “Fiber Is Not Everything: Dietary Fat Type Shown to Be Relevant for Gut Microbes.” Gut Microbiota for Health. March 14, 2019.
  8. Khansari, Nemat, Yadollah Shakiba, and Mahdi Mahmoudi. “Chronic Inflammation and Oxidative Stress as a Major Cause of Age-Related Diseases and Cancer.” Recent Patents on Inflammation & Allergy Drug Discovery 3, no. 1 (2009): 73-80. doi:10.2174/187221309787158371.
  9. Greger, Michael. “Olive Oil & Artery Function.” August 17, 2015.
  10. Murray, Jennifer. “DefiningCold-Pressed Oils.” The Spruce Eats. November 28, 2018.
  11. Yousefi, Mojtaba, and Hedayat Hosseini. “Evaluation of Hexane Content in Edible Vegetable Oils Consumed in Iran.” Journal of Experimental and Clinical Toxicology 1, no. 1 (2017): 27-30. doi:10.14302/issn.2641-7669.ject-17-1790.
  12. Casselbury, Kelsey. “The Average Fat Intake in SAD.” SF Gate. November 19, 2018.
  13. Messina, Ginny. “Fat in Vegan Diets: How Low Should You Go?” The Vegan RD. March 18, 2010.
  14. Hughes, Jason. “Fat on a Vegan Diet: Everything You Need to Know (The Complete Guide).” Vegan Liftz. December 24, 2019.
  15. Jampel, Sarah. “Is There a ‘Right’ Way to Roast Vegetables?” Food52. January 4, 2017.
  16. Edwards, Terri. “Plant-Based Tips for Cooking Without Oil.” T. Colin Campbell Center for Nutrition Studies. February 23, 2018.
  17. Oliveira, Rosane. “How to Cook Without Oil (and Never Ever Miss It!).” UC Davis Integrative Medicine. March 17, 2015.
  18. “How to Bake Without Oil.” PlantPlate. October 8.

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