Pooling 12 studies, a low-FODMAP diet lowered IBS severity by about 45 points on the 500-point IBS-SSS scale compared with control diets, and raised quality of life scores by about 5 points.
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therapeutic diets
Some diets have been tested like medicine. Here is what those trials found.
Mediterranean, DASH, ketogenic and low-FODMAP eating all have real trial evidence, and each one has a boundary that gets left out when the diet is sold. Here are the trial results on one page, including the retraction that forced the biggest Mediterranean diet trial to be republished.
12papers
11studies in people
5counterpoints
this page, by tier
- 8 human evidence
- 3 early human
- 0 lab + animal
- 1 background
the short version
what the research found
the headline numbers
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After the original paper was retracted and reanalyzed, PREDIMED still found about 30% fewer major heart events in 7,447 high-risk adults on a Mediterranean diet with olive oil or nuts than on a reduced-fat diet.
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The DASH diet lowered blood pressure by 5.5/3.0 mm Hg more than a control diet, and by 11.4/5.5 mm Hg in people with hypertension.
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In 145 children with drug-resistant epilepsy, 38% on a ketogenic diet had their seizures cut by more than half at three months, versus 6% of controls.
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On a low-FODMAP diet, gut symptom scores in people with IBS were about half those on a typical diet.
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A year of healthy low-fat versus healthy low-carb eating in 609 adults ended just 0.7 kg apart, and neither genes nor insulin predicted who did better on which.
my honest bottom line
These patterns were tested for specific outcomes in specific people, and the effects are real but narrow: blood pressure for DASH, heart events in high-risk Spanish adults for the Mediterranean diet, seizures in children for ketogenic diets, gut symptoms for low-FODMAP. The biggest limitation is that named diets rarely beat each other head to head, and a year of low-fat versus low-carb ended 0.7 kg apart.
evidence at a glance
12 papers
- human evidence8
- early human3
- lab + animalnone yet0
- background1
Includes 5 counterpoints.
every title links to the original
the papers
Sorted from the strongest human evidence down to the lab work and background reading. Counterpoints are marked, and they stay in on purpose.
Across three large US cohorts, 210,145 adults and 15,837 heart events, people whose diets scored most inflammatory had 38% more cardiovascular disease and 46% more coronary heart disease than those scoring least. It is observational, so it shows association, not cause.
The republished PREDIMED trial. After auditors found household members enrolled without randomization and uneven use of randomization at two sites, the data were reanalyzed without assuming everyone was randomized. Major heart events were 3.8% with olive oil, 3.4% with nuts and 4.4% on the control diet.
DIETFITS randomized 609 adults to a healthy low-fat or healthy low-carb diet for a year. Weight change was -5.3 kg and -6.0 kg, 0.7 kg apart, and neither a three-gene pattern nor baseline insulin secretion predicted who did better on which.
Across 13 trials lasting a year or more, very-low-carb ketogenic diets produced 0.91 kg more weight loss than low-fat diets, with lower triglycerides and higher HDL. LDL cholesterol also ran higher on the ketogenic diets.
145 children aged 2 to 16 with drug-resistant epilepsy got a ketogenic diet or usual care. At three months, 38% on the diet had more than a 50% drop in seizures versus 6% of controls. Constipation, vomiting and low energy were common, and six children stopped because they could not tolerate it.
show all 12 papersshow fewer
DASH-Sodium tested three salt levels within each diet. Compared with the control diet at high salt, DASH at low salt had systolic pressure 7.1 mm Hg lower in people without hypertension and 11.5 lower in those with it. Less salt and the DASH pattern each helped, and more together.
459 adults ate controlled diets for eight weeks with salt and weight held steady. The DASH pattern, rich in fruits, vegetables and low-fat dairy, lowered blood pressure 5.5/3.0 mm Hg more than the control diet, and 11.4/5.5 mm Hg more in the 133 people with hypertension.
17 men lived on a research ward, first on a high-carb diet, then a ketogenic diet at the same calories. Energy use rose only 57 to 151 calories a day, near the limit of detection, and body fat loss slowed on the ketogenic diet, the opposite of what the carbohydrate-insulin model predicts.
30 people with IBS ate a low-FODMAP diet and a typical Australian diet for three weeks each, with nearly all food provided. Symptom scores were 22.8 on low-FODMAP versus 44.9 on the typical diet, out of 100, with a level of food control nobody reproduces at home.
In 41 people with IBS, more reported adequate symptom control after four weeks of fermentable carb restriction (68%) than on their usual diet (23%). But gut bifidobacteria dropped on the restricted diet, which is the argument against staying on it long term.
The formal retraction of the 2013 PREDIMED paper, paired with the republished version above. It is the primary document for anyone checking why the original is no longer citable.
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This page summarizes published research for education. It is not medical advice, and nothing here describes what any nanonourish™ product does. Talk with your care provider before changing your diet or starting a supplement, especially if you are pregnant, nursing or taking medication. Summaries by Dr. Kaylan Jackson, PhD, a chemist, not a physician. Citations checked against PubMed and Crossref, September 2026.