Do meat cravings mean your body needs meat?

The objection

“I crave meat constantly. That’s my body telling me it needs it. It’s natural, we evolved to eat it, and you can’t fight biology.”

The answer

Humans evolved as omnivores, as the answer on whether humans are meant to eat meat sets out, and evolution left us with other appetites too. Children are born preferring sweet tastes, and they prefer higher levels of sweetness than adults do until their middle to late teens (Mennella and Bobowski, 2015) [1]. That preference is rooted in their biology, yet the same review calls it often detrimental in the modern food environment, where children eat more sugar than health organisations worldwide recommend [1]. How deep an urge runs explains why it is hard to ignore, not whether acting on it is right, and avoiding needless harm means overriding plenty of urges that feel natural. The weaker half of the objection is the idea that the craving is your body reporting a need.

Does craving meat mean your body needs it?

A meat craving rarely means your body needs meat, going by the research on food cravings in general. A 2020 review by Adrian Meule of LMU Munich’s university hospital found the evidence that cravings come from nutrient deficiencies “relatively poor”, and concluded that deficiencies account for a small fraction of cravings at most [2]. Volunteers on a nutritionally balanced but monotonous liquid diet reported more cravings than before it, people who had already eaten could be made to crave a favourite food just by imagining it, and pregnant women, who need more energy and some nutrients than usual, seem to crave much the same foods as everyone else [2]. What people crave also follows culture: chocolate is the most commonly craved food in the studies the review cites, but in Japan rice comes first [2].

Iron deficiency can bring on a craving, but the one the UK’s NHS lists is for non-food items such as paper or ice, known as pica, which it counts among the less common symptoms of iron deficiency anaemia [3]. In a 2010 study of 262 adults treated for iron deficiency or low iron stores at a clinic in Birmingham, Alabama, 45% reported pica and 87% of those craved ice, and the authors note that most things people with pica crave contain little or no iron (Barton and colleagues) [4]. Tiredness and shortness of breath are commoner symptoms, and the NHS advises anyone who thinks they might have it to see a GP, who will usually do a blood test [3].

On whether you need meat at all, the British Dietetic Association says carefully planned plant-based diets can support healthy living at every age and life stage [7]. The planning matters: a 2021 systematic review of 141 studies by two Unilever scientists found that people on plant-based diets ate less protein than meat-eaters, though well within recommended levels, and generally had lower intakes or levels of B12, vitamin D, iron, zinc, iodine and calcium, while meat-eaters risked falling short on fibre, folate, vitamin D, vitamin E, calcium and magnesium [6]. Vegans need B12 from fortified foods or a supplement, the only reliable sources according to the association [7], and since they tend to store less iron than meat-eaters [6], it pays to know where yours comes from.

Why do I crave meat?

Studies of food cravings in general point to learning: cues that have often come with eating meat, such as hunger or the time of day, can come to set off a craving for it by themselves [2]. This is called conditioning, and the main psychological explanations of food cravings rest on it [2]. Driving and watching television can become cues too [5], and in theory any cue can, the 2020 review notes, with laboratory studies tying the desire to eat to geometric shapes [2]. For someone who has eaten meat all their life the cues are everywhere, from the smell of a fry-up to the Friday takeaway.

Do meat cravings go away?

Meat cravings will probably fade with time, if they behave like the food cravings researchers have studied, though they can get stronger first. In short experiments in which university students gave up one food, such as chocolate, rice or bread, for between one and 14 days, almost every study found the craving for it rose, mostly in people already prone to cravings [2]. Weight-loss studies lasting from four weeks to two years mostly found the reverse, with cravings falling mainly in the first weeks, and in the studies that followed people up for a few months afterwards they did not seem to rebound [2]. Meule’s reading is that going without a food for at least several weeks may undo the learned link between cue and food, which takes longer to unlearn than it took to learn [2].

In the POUNDS Lost trial in the US, where adults with overweight or obesity followed one of four weight-loss diets for two years, cravings for high-fat foods such as fried chicken and sausage fell on all four diets (Anton and colleagues, 2012) [5][8]. An analysis of 367 of the participants found that the less often people ate a craved food, the less they craved it (Apolzan and colleagues, 2017) [5]. The link was small, and clearest for sweets, and for fast food such as pizza, chips and hamburgers at six months; for the group that included fried chicken and sausage it fell short of statistical significance [5]. Eating smaller amounts made no difference overall, though it did for sweets, and at two years for that same group [5]. By two years, as people regained some weight, the fall in overall cravings was much smaller than at six months, but the link with how often people ate a food still held [5].

These studies looked at dieters and at students giving up a single food for up to two weeks, and none of them followed people going vegan. Apolzan and colleagues advise eating a craved food less often to weaken the craving, though they call their data correlational and say trials are needed to confirm it [5].