Fibre supplements are among the weight-loss products with a fair claim to the name magic pill, because some fibre products show a measurable result when trials are pooled. The results are small, though. And fibre is not something you can only buy in a tub: dates and plenty of other ordinary foods carry it too.
Why fibre supplements get recommended
A 2014 review by Onakpoya, Posadzki and Ernst (PubMed 24533610) starts from the market. Dietary supplements marketed as weight reducing agents are popular, the authors write, and the efficacy of most of them is not established. Glucomannan, a soluble fibre, is often recommended for weight loss, so they went looking for the evidence for and against it.
Glucomannan, two reviews apart
They identified 18 trials and included 9. Pooling 8 of them gave a difference of 0.22 kg between glucomannan and placebo, and that difference was not statistically significant. The side effects reported were abdominal discomfort, diarrhoea and constipation. Their conclusion was blunt: the trials do not show that glucomannan produces statistically significant weight loss, and future trials should be more rigorous and better reported.
A much larger network meta-analysis from 2023, by Shahinfar and colleagues (PubMed 37778464), brought together 111 trials with 6,171 participants covering 18 supplements. There, glucomannan came out at 1.36 kg, with the certainty of the evidence rated low. Nine years on, the answer had moved from no clear effect to a small, shaky one.
The same analysis put psyllium at 3.70 kg with moderate certainty. Spirulina was the only supplement with high-certainty evidence, at 1.77 kg. The authors' overall summary was that these products can result in a small weight loss in adults with overweight or obesity.
Fibre added to a smaller plate
Jovanovski and colleagues (PubMed 32198674) asked a narrower question in 2021. What happens when viscous fibre supplements are added to a calorie-restricted diet for at least four weeks? Across 15 studies with 1,347 people, body weight fell 0.81 kg more than in the comparison groups and body fat fell by 1.39%. Waist circumference did not change. The authors graded the certainty for body weight as moderate.
Look at the setup. Every one of those results was measured inside a reduced-calorie diet. The supplement was added to the diet, not used in place of it.
The same nutrient on a normal plate
The NHS fibre page says government guidelines put dietary fibre at 30g a day, while most adults eat an average of about 20g. It also gives a simple label rule: high-fibre foods have 6g or more of fibre in every 100g.
Dates clear that line. In USDA FoodData Central, Deglet Noor has 8.0g of fibre per 100g (FDC 171726) and Medjool has 6.7g (FDC 168191). A 30g portion of Deglet Noor works out at about 2.4g of fibre and 85 kcal. These are total dietary fibre figures, while the trials above tested particular fibre supplements, so the numbers do not carry over one for one.
The NHS 5 A Day page counts a 30g portion of dried fruit, dates among them, as one portion. It adds that dried fruit should be eaten at mealtimes, not as a snack between meals, to reduce the impact on teeth. For the rest of the 30g, the fibre page points to wholemeal or granary bread, wholewheat pasta, bulgur wheat or brown rice, porridge oats, and vegetables added to sauces, stews or curries.
What about the juice bar?
Blending fruit does not make it a better version of itself. The NHS limits fruit juice, vegetable juice and smoothies to a combined 150ml a day, because crushing fruit and vegetables releases the sugars they contain, and it keeps them to mealtimes as well. For dessert, the fibre page suggests fresh or dried fruit.
Keeping dates in the cupboard
Kurma Online covers everything from retail buying to wholesale supply, with delivery across the country, as its about page explains. Questions, quotes and orders go through WhatsApp, and the number is on the contact page. Older articles are on the blog. One more link, kept from the earlier version of this post: Pembekal Kurma Selangor.
This article is general information about published research, not personal advice. If you have a health condition or take regular medication, check with your doctor before starting a supplement or changing your diet.