Oat oil: the appetite emulsion that later trials did not confirm

Most human research with oat oil in it is about Olibra, also sold as Fabuless, an emulsion of palm and oat oil marketed to curb appetite. It is mostly palm oil, so none of its results are results for oat oil alone. The early randomized trial looked good. In 50 overweight women who had just dieted, weight regain over 18 weeks was 2.4 lb (1.1 kg) on the emulsion against 6.6 lb (3.0 kg) on placebo. Later trials did not repeat it. In 82 overweight adults over 12 weeks, 2.1 g twice a day gave 4.8 lb (2.17 kg) of weight loss against 3.7 lb (1.68 kg) on placebo, a gap that did not reach significance, and only 71 of the 82 were analyzed. In 18 lean men, and again in two trials of 24 volunteers each, the emulsion did not reduce how much people ate or how hungry they felt. The EU refused both claims made for it, that it helps you eat less and that it prolongs fullness.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• USDA lists oat oil as 100 g of fat per 3.5 oz (100 g), of which 19.6 g is saturated, with 14.4 mg of vitamin E and 24.7 micrograms of vitamin K. — USDA SR Legacy record Oil, oat (n = 1 record) Evidence E source
  Fat 100 g, saturated fat 19.62 g, vitamin E 14.4 mg (96% DV), vitamin K 24.7 ug (21% DV) per 3.5 oz (100 g)
• Laboratory analysis of oils from 16 oat cultivars found oleic acid at about 41% and linoleic acid at about 39% of the fatty acids on average. — oils extracted from 16 oat cultivars grown in China (n = 16 cultivars) Evidence D source
  Oleic acid 40.89% and linoleic acid 38.53% (means), palmitic, oleic and linoleic together over 90%

What your body absorbs

• In a crossover RCT on 15 healthy men, a palm and oat oil emulsion slowed transit from mouth to colon by about 45 minutes against milk fat. — 15 healthy men aged 20 to 59, BMI 22 to 28, two test days one week apart (n = 15) Evidence B source
  Orocecal transit time 45 min longer

What cooking and storage change

• In a crossover RCT on 24 volunteers, the authors found the palm and oat oil emulsion lost its effect on food intake after heat and shear processing, and only the unprocessed form lowered dinner intake. — 24 healthy volunteers (16 female, 8 male), aged 18 to 43, yogurt drinks with processed or unprocessed emulsion (n = 24) Evidence B source
  Dinner energy intake: control 4.3 MJ, processed 3.9 MJ, unprocessed 4.2 MJ (only unprocessed reported significant), no change at lunch

What it does to your health

• In a crossover RCT on 20 healthy young adults, adding 15 g of oat polar lipids to a bread breakfast lowered blood glucose and insulin over 2 hours compared with rapeseed oil. — 20 young healthy subjects, single test breakfasts with 7.5 or 15 g oat polar lipids vs rapeseed oil (n = 20) Evidence B source
  Lower glucose and insulin iAUC 0 to 120 min with 15 g (p < 0.05), lower triglycerides and ghrelin, higher GLP-1 and PYY; size in mmol not given in abstract
• In a 12-week RCT on 82 overweight adults, 2.1 g of the palm and oat oil emulsion twice a day gave no weight loss beyond placebo, 4.8 lb (2.17 kg) against 3.7 lb (1.68 kg). — 82 enrolled, 71 analyzed, aged 18 to 60, BMI 25 to 40, 12 weeks (n = 82) Evidence B source
  Weight -4.8 lb (-2.17 kg) test vs -3.7 lb (-1.68 kg) placebo, difference not significant
• An earlier RCT on 50 overweight women found the palm and oat oil emulsion limited weight regain after dieting to 2.4 lb (1.1 kg) against 6.6 lb (3.0 kg) on placebo over 18 weeks. — 50 overweight women aged 18 to 58, BMI 25 to 32, 6 weeks of weight loss then 18 weeks maintenance (n = 50) Evidence B source
  Regain 2.4 lb (1.1 kg) (SD 3.4) test vs 6.6 lb (3.0 kg) (SD 3.1) placebo

What people believe that the data does not support

• In a crossover RCT on 18 lean men, the palm and oat oil emulsion taken before breakfast did not reduce how much they ate or make them stop eating sooner. — 18 lean men, 4 preloads before an ad libitum breakfast (n = 18) Evidence B source
  No difference in energy intake or meal termination vs energy-matched lipid control (P > 0.05)
• In two crossover RCTs on 24 volunteers each, the palm and oat oil emulsion in minimally processed drinks had no effect on appetite or food intake. — two studies of 24 healthy volunteers each (16 female, 8 male) (n = 48) Evidence B source
  No significant effect on food intake or appetite
• The EU refused the claim that a palm and oat oil emulsion helps people eat less and avoid weight regain after dieting. — EU Register on nutrition and health claims Evidence E source
  Claim non-authorized
• The EU also refused the claim that palm and oat oil fatty acids increase and prolong the feeling of fullness. — EU Register on nutrition and health claims Evidence E source
  Claim non-authorized

Who this works differently for

• In a crossover RCT on 28 non-obese adults over two 3-week phases, the palm and oat oil emulsion had no average effect on lunch intake, with only 46 to 59% of people eating less. — 28 non-obese subjects (14 male, 14 female), 5 g emulsion fat in yogurt daily for 2 x 3 weeks (n = 28) Evidence B source
  No significant effect on mean energy intake; 46%, 59% and 57% reduced intake at lunch on days 1, 8 and 22

The bottom line

As a cooking oil it is almost pure fat. USDA lists 100 g of fat per 3.5 oz (100 g), 19.6 g of it saturated, with 14.4 mg of vitamin E, 96 percent of the Daily Value in those 3.5 oz (100 g) of oil, from a single legacy record with no measured spread. In oils extracted in the lab from 16 Chinese oat cultivars, oleic acid averaged about 41 percent and linoleic acid about 39 percent of the fatty acids, and commercial oat oil may differ. A few small trials test parts of the story. Adding 15 g of oat polar lipids, a fraction of oat oil, to a bread breakfast lowered blood glucose and insulin over the next 2 hours compared with rapeseed oil in 20 healthy young adults. That was one meal, the abstract gives no size in mmol, and the research group has industry links. In 15 healthy men the palm and oat emulsion slowed transit from mouth to colon by about 45 minutes against milk fat, after a single dose. One crossover trial in 24 volunteers reported that the emulsion lowered dinner intake only when unprocessed, yet the processed version sat lower on the same table, 3.9 MJ against 4.2 MJ, so those numbers do not line up with the stated result. In 28 non-obese adults given 5 g of emulsion fat a day for two 3-week phases, average lunch intake did not change, and the 46 to 59 percent who ate less on a given day is a split close to half, which chance alone could produce. We found no evidence at all on oat oil and allergy, pregnancy, children, kidney disease or medicines, so this page has no safety section. Read that as missing data.

Sources

1. oto-r2-01 · USDA FoodData Central SR Legacy, dataset
   Oil, oat (FDC 173576, SR Legacy, Fats and Oils): total fat 100 g per 100 g = 128% DV; saturated fat 19.62 g = 98% DV; vitamin E 14.4 mg = 96% DV; vitamin K 24.7 ug = 21% DV; Foundation samples 0, CoFID match none
   USDA FoodData Central, SR Legacy, FDC 173576 · checked 2026-09-29
2. oto-r2-02 · food chemistry analysis
   The oat oils were particularly rich in monounsaturated oleic acid (C18:1) and polyunsaturated linoleic acid (C18:2), which constituted approximately 40.89 ± 0.02% and 38.53 ± 0.01% of the total oil content, respectively.
   Foods, 2025 · checked 2026-09-29
3. oto-r2-04 · RCT
   A statistically significant delay in the appearance of sulfapyridine in serum was obtained after active treatment versus control treatment, corresponding to a 45-min longer orocecal transit time due to fat emulsion consumption.
   Scand J Gastroenterol, 2009 · checked 2026-09-29
4. oto-r2-05 · RCT
   Compared with control, only unprocessed Fabuless reduced subsequent energy intake, although only during dinner (P < 0.01; control, processed and unprocessed: 4.3, 3.9 and 4.2 MJ, respectively) and not during lunch (3.6, 3.7 and 3.6 MJ).
   Eur J Clin Nutr, 2011 · checked 2026-09-29
5. oto-r2-03 · RCT
   After breakfast, PLH substantially lowered postprandial glucose and insulin responses (iAUC 0-120 min) compared with RSO and WWB (p < 0.05).
   Nutrients, 2023 · checked 2026-09-29
6. oto-r2-06 · RCT
   At 12 weeks, body weight was reduced in the test group (2.17 ± 0.46 kg standard error of the mean, p < .0001) and the control group (1.68 ± 0.42 kg, p < .0001).
   J Diabetes Sci Technol, 2012 · checked 2026-09-29
7. oto-r2-09 · RCT
   During weight maintenance after significant body weight reduction, there was no significant increase in body weight in the test group (1.1+/-3.4 kg); the placebo group did gain weight (3.0+/-3.1 kg, P<0.001).
   Int J Obes (Lond), 2007 · checked 2026-09-29
8. oto-r2-07 · RCT
   When consumed with a meal there was no evidence in lean men that this commercial lipid emulsion promotes satiation or suppresses short-term food intake.
   Physiol Behav, 2015 · checked 2026-09-29
9. oto-r2-08 · RCT
   The structured lipid emulsion tested had no significant effect on the primary measures of food intake or appetite.
   Int J Obes (Lond), 2012 · checked 2026-09-29
10. oto-r2-11 · EU claims register
    POL-HC-7119 Formulated palm and oat oil emulsion Helps to eat less. Helps to reduce weight regain after dieting. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7119, snapshot 2026-09-21 · checked 2026-09-29
11. oto-r2-12 · EU claims register
    POL-HC-7717 Palm/oat oil fatty acid In studies found to increase and prolong the sense of satiety. Helps to control appetite during the day. Increases the feeling of satiety Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7717, snapshot 2026-09-21 · checked 2026-09-29
12. oto-r2-10 · RCT
    There was considerable individual variation in food intakes following consumption of the Olibra emulsion, with 46, 59 and 57% of subjects reducing their energy intakes at lunch on days 1, 8 and 22.
    Eur J Clin Nutr, 2006 · checked 2026-09-29