Industrial trans fats come mainly from partial hydrogenation, which turns liquid oil into solid fat such as vanaspati and bakery shortening, and in small amounts from very high-temperature refining and repeated frying. FSSAI caps industrial trans fat at 2 per cent of total fat in edible oils and fats. Check ingredient lists for hydrogenated fat, not just front-of-pack claims.
Last updated: 6 Oct 2026 | Shop cold pressed groundnut oil
Trans fat is the one fat that almost every health body agrees you should keep as low as possible, and it is also a term that gets used loosely on food packets. This page explains in plain language what trans fats are, where they come from in cooking oils and packaged foods, what India’s food regulator has actually said about them, and what to look at on a label.
We press unrefined oil at our own mill in Nagpur, so we have a stake in this subject. We have kept to documented facts and to what the regulation covers, and we say where the picture is less clear than the headlines.
What are trans fats?
Trans fats are a type of unsaturated fat whose molecules have a different shape from the ones in a normal liquid oil. Small amounts occur naturally in the fat of milk and meat from ruminant animals such as cows and buffaloes. The ones that health authorities are concerned about are industrial trans fats, which are created by food processing.
The reason regulators single them out is that industrial trans fat raises LDL cholesterol, lowers HDL cholesterol and is linked to heart disease. The World Health Organization recommends keeping total trans fat intake below 1 per cent of daily energy, which for a 2,000 kilocalorie diet works out to about 2 grams a day, and has called for industrial trans fat to be eliminated from the food supply.
Where do industrial trans fats come from?
| Source | How trans fat forms | Comment |
|---|---|---|
| Partially hydrogenated fat (vanaspati, bakery shortening, some margarines and spreads) | Hydrogen is added to liquid oil to make it solid; the partial process creates trans fat | Historically the largest source, and the main target of the regulation |
| Refined oil | Prolonged high-temperature deodorising can form small amounts | Much lower than in hydrogenated fat |
| Repeated deep frying | Oil heated many times at high temperature breaks down and can form trans fats and other compounds | A household and street-food issue, not a product label issue |
| Cold pressed oil | No hydrogenation, no high-temperature deodorising | Not a source of industrial trans fat when used normally |
Notice that the main source is not the liquid oil in a bottle. It is solid fat used in fried snacks, biscuits, cakes and other packaged foods. That matters when you decide where to look.
What does the FSSAI limit say?
India’s food regulator, FSSAI, set a limit on industrial trans fat that was phased in over two years: no more than 3 per cent of total fat by January 2021, and no more than 2 per cent by January 2022. The limit applies to edible refined oils, vanaspati, bakery shortening, margarines and fat spreads.
Two points are worth understanding. First, the limit is a cap and not a zero: a fat that is 2 per cent trans can still be sold. As arithmetic, 20 grams of such an oil would contain at most 0.4 grams of trans fat. Second, a limit on the fat used in a product is not the same as a limit on how much trans fat you eat in total, which depends on how many fried and packaged foods are in your diet.
Complying with a limit does not make a product good for everyday eating, and it is reasonable to prefer foods with no hydrogenated fat at all.
How to spot trans fat on a label
- Look in the ingredient list for “partially hydrogenated vegetable fat or oil”, “hydrogenated vegetable fat”, “vanaspati”, “bakery shortening” or “margarine”. These are the ingredients that carry industrial trans fat.
- Check the nutrition information panel, which lists trans fat alongside saturated fat. Compare packs on the per-100 gram figures so the serving size does not hide anything.
- Read the ingredients, not just the claim. A bold “trans fat free” statement on the front tells you less than the ingredient list on the back.
- Ignore “cholesterol free”. Every vegetable oil is cholesterol free, so the phrase says nothing about trans fat or about how the oil was made.
- Be careful with fried and baked packaged foods, such as namkeen, biscuits, cakes and puffs, where shortening is common. Our guide to how to read a cooking oil label covers the cooking oil bottle itself.
Refined oil, cold pressed oil and trans fats
It helps to be precise here. The edible oil you buy in a bottle is generally a liquid oil and is not partially hydrogenated, so it is not the same as vanaspati. Refining can form small amounts of trans fat during deodorising, which is one of the processing by-products we describe in chemicals in refined oil: what is used and what remains, but those amounts are far lower than in hydrogenated fat, and the regulator’s limit applies to refined oils.
Cold pressed oil avoids both routes. It is pressed mechanically at low heat and only filtered, so there is no hydrogenation and no high-temperature deodorising step. That makes it a reasonable choice if you want to avoid industrial trans fat from the oil you cook with. It does not, however, change the larger picture: what matters most is the fried and packaged food in your diet. We explain the wider processing differences in what is refined oil and how it is made and our overview of the hazards people associate with refined oil.
How to keep trans fat low at home
- Cook with a liquid oil, not a solid fat, for everyday dishes. Avoid using vanaspati or shortening as your default cooking fat.
- Cut down on packaged fried and baked snacks, and check the ingredient list for hydrogenated fat whenever you buy them.
- Do not reuse frying oil repeatedly. FSSAI’s guidance on used cooking oil says oil should be discarded once its total polar compounds pass 25 per cent and advises avoiding repeated use for frying. For households, it suggests filtering the oil after one round of frying and using the leftover for a curry.
- Do not overheat oil. Heat it gradually and take the pan off if it smokes. Our guide to the smoke point of cooking oils shows how hot different oils can go.
- Buy oil from a producer who tells you how it is made. Ask where it is pressed, and read our guide to testing cold pressed oil at home before trusting a label.
What we do at our mill
At our mill in Hudkeshwar, Nagpur, seeds are pressed in a wooden ghani that turns slowly so friction heat stays low. The oil is filtered, rested and bottled on the same site. There is no hydrogenation, no solvent, no bleaching and no deodorising. You can see each step on our Nagpur oil mill page.
If you want a starting point, cold pressed groundnut oil covers everyday Indian cooking, and mustard oil and sesame oil suit specific dishes. We do not claim that any oil prevents or cures disease. Our claim is narrower and easy to check: it is pressed and filtered, with nothing added.
Frequently asked questions
What are trans fats in cooking oil?
Trans fats are a type of unsaturated fat that raises LDL cholesterol and lowers HDL cholesterol. The industrial kind is made by partially hydrogenating liquid oil into solid fat, and smaller amounts can form during very high-temperature refining or repeated frying. Small natural amounts also occur in milk and meat fat.
What is the FSSAI limit for trans fat in oil?
FSSAI limits industrial trans fat to no more than 2 per cent of total fat, phased in from 3 per cent by January 2021 to 2 per cent by January 2022. It applies to edible refined oils, vanaspati, bakery shortening, margarines and fat spreads. The limit is a cap, not a zero.
Do cold pressed oils contain trans fat?
Cold pressed oil is not hydrogenated and does not go through high-temperature deodorising, so it is not a source of industrial trans fat when used normally. Any oil can form trans fats and other compounds if heated hard and reused repeatedly, so avoid overheating and repeated frying.
Is vanaspati the same as trans fat?
Vanaspati is a solid cooking fat traditionally made by partially hydrogenating vegetable oil, which is why it has historically been a major source of industrial trans fat. It is covered by the FSSAI limit. Check the label, because formulations vary, and prefer liquid oils for everyday cooking.
How can I tell if a packaged food has trans fat?
Read the ingredient list for partially hydrogenated or hydrogenated vegetable fat, vanaspati, bakery shortening or margarine, and check the trans fat line in the nutrition panel on a per-100 gram basis. A front-of-pack claim alone is not enough, so trust the ingredients on the back.
Does reusing frying oil create trans fats?
Prolonged high-temperature heating, especially over repeated rounds of frying, can form small amounts of trans fats along with other breakdown compounds. FSSAI advises avoiding repeated use of frying oil and discarding it once total polar compounds pass 25 per cent. At home, filter the oil after one use and use the leftover for a curry.
Written by Dushyant Waghmare, founder — Parampara Naturals, who operates a wooden ghani oil mill in Nagpur.
Last updated: 6 Oct 2026