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Dr Zoe Harcombe: ‘Why the Eat-Lancet plant-based diet is nutritionally deficient’

The EAT-Lancet Commission released details of the controversial Eat-Lancet diet in January. Here, ahead of the College of Medicine’s Food On Prescription Conference in October 2019, author and researcher Dr Zoe Harcombe, who specialises in examining public health dietary guidelines, casts a critical eye over it…

In January 2019 this year, the Eat-Lancet diet was launched to great fanfare as the Commission behind it tries to reduce global meat consumption by 90 per cent

Earlier this year, The Lancet commissioned a report that was written by 37 people from 16 different countries and was 3 years in the making (Ref 1). It was released and promoted with much fanfare as ‘The Eat-Lancet Diet’.

The following table is an extract from the report. This shows what the researchers think a healthy adult requiring 2,500 calories a day should be eating.


The USDA (United States Department of Agriculture) has a useful database of tens of thousands of foods. I used this database to analyse the nutritional contributions of the diet proposed in Table 1.

I selected the foods as closely to Table 1 in the Lancet report as possible, using the table notes to select foods (e.g. the 40g of unsaturated oils were specified as 8g each of olive, soybean, rapeseed, sunflower and peanut oils.) I used the calorie intake column in the table to ensure that I had got as closely as possible to the line item in the Lancet table (some lines are within 1 calorie!)

I then aggregated macro and micronutrients found in all these amounts of all these different foods. This is shown below:

EAT diet nutritional info


The ‘Healthy’ reference (EAT) diet (based on 2,500 calories, so for an adult male) has the following macronutrient composition: 

As a % of calories14%35%51%


Because the EAT diet is based on an adult male, an adult female would likely consume four fifths of the proposed diet and thus four fifths of the proposed vitamins and minerals. Notwithstanding this, the above diet is deficient in the following nutrients:

Vitamin B12 – the US RDA (Recommended Daily Allowance) is 2.4mcg, the EAT diet is slightly deficient in providing 2.27mcg.

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I would not mention this nutrient but for the comment in Table 1 that animal items can be replaced with plant protein options and these will not provide any B12. (There was an amusing error on p16 of the 51-page report, which has been corrected since I pointed it out to The Lancet. It said, “The only exception is vitamin B12 that is low in animal-based diets.” That’s should have said plant-based diets!)

Retinol (Vitamin A) – The EAT diet provides just 17% of retinol recommended – carotene conversion cannot be relied upon.

Vitamin D – the EAT diet provides just 5% of vitamin D recommendation and some of that provided will have come from plants and not be D3, which is the body’s preferred form.

Vitamin K – the USDA is not ideal when it comes to vitamin K, as it does not distinguish between K1 and K2. 72% of the vitamin K in the EAT diet came from the broccoli (K1). As is the case with all nutrients, the animal form (K2) is better absorbed by the body.

Sodium – the EAT diet provides just 22% of the sodium recommendation. This is, at least, easily rectifiable.

Potassium – the EAT diet provides just 67% of potassium recommended. This too is fairly easy to rectify, which only adds to the bafflement that 37 researchers didn’t think to check nutrient provision.

Calcium – more seriously, the EAT diet provides just 55% of calcium recommended. 

Iron – the paltry amounts of beef, pork, chicken and fish provided a maximum of 1.1mg of heme iron. The US recommendations state: “The RDAs for vegetarians are 1.8 times higher than for people who eat meat. This is because heme iron from meat is more bioavailable than nonheme iron from plant-based foods, and meat, poultry, and seafood increase the absorption of nonheme iron” (Ref 2). Barely half the iron intake for females would be provided.

Essential fatty acids – 28g of fish cannot provide the EPA and DHA required (the form in which the body wants omega-3), while the nutritionally poor 350 calories of highly unsaturated fats would create an unhealthy omega-6 to omega-3 ratio. Fish is the best source of omega-3 and the 28g of fish in the EAT diet provides 284mg of omega-3 fatty acids vs. an RDA of 1.6g for adult males (Ref 3).  

The EAT Lancet diet recommends more calories from added sugar (120) than from beef, lamb, pork, chicken, other poultry and eggs all added together (111)! 

There are numerous other issues with this plant-biased advice. Not least – what will all these plants be grown in when there is no topsoil left because we have replaced soil-rejuvenating ruminants with soil-raping plants? (Ref 4)

This article is based on an original piece published on January 17 2019 on


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