The paleo diet takes its name from the Paleolithic, the Old Stone Age. In the research trials, it means eating lean meat, fish, fruit, vegetables, root vegetables, eggs and nuts, and leaving out grains, dairy and processed foods. Whether that is healthy depends on two things: what it is compared with, and for how long. This article goes through what the trials measured, what the plan drops, and how dates fit into it.
What the trials compared it with
In 2015, Manheimer and colleagues pooled four randomised trials for the American Journal of Clinical Nutrition. Between them, the trials had 159 participants, each with at least one of the five components of metabolic syndrome. Every control diet was based on a national nutrition guideline. Measured at six months or earlier, the paleo groups lost more from the waist (about 2.4 cm more) and had a larger fall in triglycerides, a type of blood fat. The other measures, fasting blood sugar among them, had confidence intervals that crossed zero, so the trials did not show a clear difference there. The reviewers rated the evidence as moderate quality and called for more study.
A 2019 review in Nutrition Journal (de Menezes and colleagues) put 11 randomised studies into its meta-analysis. People on the paleo diet lost an average of 3.52 kg more than people on diets based on official recommendations. The authors still wrote that larger and longer trials are needed before the health benefits can be called proven.
What happens over two years
Manheimer's review used results from six months or earlier. One trial ran for two years. Otten and colleagues randomised 70 healthy postmenopausal women with obesity to either a paleo diet or a conventional low-fat diet, with no limit on how much they ate. Liver fat was measured in the 41 women who finished those scans. At six months it had dropped by 64% in the paleo group and by 43% in the low-fat group, a real difference. At two years the figures were 50% and 49%. By then the gap between the diets had all but disappeared.
What the plan leaves out
Grains and pulses are not on the menu. A 2019 trial of 39 women by Genoni and colleagues pointed out that these are two major sources of fibre, and the women on the paleo diet ate significantly less resistant starch over four weeks. Dairy is gone too. In a small 2009 crossover study by Jönsson and colleagues, the paleo diet was lower in calcium than the guideline-based diet it was compared with.
The NHS counts starchy foods as a source of fibre, calcium, iron and B vitamins, and calls milk, cheese and yoghurt an important source of calcium. Its general warning fits here: completely cutting out any type of food could mean missing out on nutrients you need. If grains and pulses go, fruit, vegetables and nuts have to supply that fibre. Our post on keeping up a higher fiber diet has a fibre table for everyday foods, including two kinds of dates.
Where dates fit on a paleo plate
The diet in Jönsson's study listed fruit without naming types, and dates are a fruit. They carry a lot of sugar for their weight. USDA FoodData Central gives these figures per 100 g:
| Per 100 g | Energy | Total sugars | Fibre | One pitted date |
|---|---|---|---|---|
| Medjool | 277 kcal | 66.5 g | 6.7 g | 24 g |
| Deglet Noor | 282 kcal | 63.4 g | 8.0 g | 7.1 g |
The NHS names dates among the dried fruits that count towards 5 A Day. A 30 g portion is one portion, and the NHS says to eat it at mealtimes rather than as a snack between meals, to reduce the risk of tooth decay. That 30 g is about one and a quarter Medjool, or about four Deglet Noor. Medjool is large and very soft with a rich caramel taste. Deglet Noor comes from Tunisia and Algeria and is golden and semi-dry. A few chopped dates over a fruit and nut bowl at breakfast keeps them at a meal.
So, is the paleo diet healthy?
In the pooled trials it did better than guideline-based diets on waist size and weight. The reviewers still asked for larger and longer trials, and the two-year trial saw its liver-fat advantage fade. It also removes grains, pulses and dairy, which the NHS treats as everyday sources of fibre and calcium. Followed strictly, it swaps one set of foods for another. The paleo trial diets and the NHS Eatwell Guide do agree on plenty of fruit, vegetables and fish.
This is general food information, not medical advice. Anyone with a health condition should talk to a doctor before making a big change to their diet.
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