Is TikTok right?

By Evangeline Mantzioris

Cinnamon has been long used around the world in both sweet and savoury dishes and drinks.

But a new TikTok trend claims adding a teaspoon of cinnamon to your daily coffee (and some cocoa to make it more palatable) for one week can help you burn fat. Is there any truth to this?

There are two types of cinnamon, both of which come from grinding the bark of the cinnamomum tree and may include several naturally occurring active ingredients.

Cassia cinnamon is the most common type available in grocery stores. It has a bitter taste and contains higher levels of one of the active ingredients cinnamaldehyde, a compound that gives cinnamon its flavour and odour. About 95 per cent of cassia cinnamon is cinnamaldehyde.

The other is Ceylon cinnamon, which tastes sweeter. It contains about 50-60 per cent cinnamaldehyde.

A review of 35 studies examined whether consuming cinnamon could affect waist circumference, which is linked to increased body fat levels. It found cinnamon doses below 1.5 grams per day (around half a teaspoon) decreased waist circumference by 1.68cm. However, consuming more than 1.5g/day did not have a significant effect.

A meta-analysis of 21 clinical trials with 1,480 total participants found cinnamon also reduced body mass index (BMI) by 0.40kg/m² and body weight by 0.92kg. But it did not change the participants’ composition of fat or lean mass.

Another umbrella review, which included all the meta-analyses, found a small effect of cinnamon on weight loss. Participants lost an average of 0.67kg and reduced their BMI by 0.45kg/m².

So overall, the weight loss we see from these high-quality studies is very small, ranging anywhere from two to six months and mostly with no change in body composition.

The studies included people with different diseases, and most were from the Middle East and/or the Indian subcontinent. So we can’t be certain we would see this effect in people with other health profiles and in other countries. They were also conducted over different lengths of time from two to six months.

The supplements were different, depending on the study. Some had the active ingredient extracted from cinnamon, others used cinnamon powder. Doses varied from 0.36g to 10g per day.

They also used the two different types of cinnamon – but none of the studies used cinnamon from the grocery store.

There are several possible mechanisms.

It appears to allow blood glucose (sugar) to enter the body’s cells more quickly. This lowers blood glucose levels and can make insulin work more effectively.

It also seems to improve the way we break down fat when we need it for energy.

Finally, it may make us feel fuller for longer by slowing down how quickly the food is released from our stomach into the small intestine.

Cinnamon is generally regarded as safe when used as a spice in cooking and food.

However, in recent months the United States and Australia have issued health alerts about the level of lead and other heavy metals in some cinnamon preparations.

Lead enters as a contaminant during growth (from the environment) and in harvesting. In some cases, it has been suggested there may have been intentional contamination.

Some people can have side effects from cinnamon, including gastrointestinal pain and allergic reactions.

One of the active ingredients, coumarin, can be toxic for some people’s livers. This has prompted the European Food Authority to set a limit of 0.1mg/kg of body weight.

Cassia cinnamon contains up to one per cent of coumarin, and the Ceylon variety contains much less, 0.004 per cent. So for people weighing above 60kg, 2 teaspoons (6g) of cassia cinnamon would bring them over the safe limit.

Many people may think coffee can also help us lose weight. However, there isn’t good evidence to support this yet.

An observational study found drinking one cup of regular coffee was linked to a reduction in weight that is gained over four years, but by a very small amount: an average of 0.12kg.

Good-quality cocoa and dark chocolate have also been shown to reduce weight. But again, the weight loss was small (between 0.2 and 0.4kg) and only after consuming it for four to eight weeks.

Using cinnamon may have a very small effect on weight, but it’s unlikely to deliver meaningful weight loss without other lifestyle adjustments.

We also need to remember these trials used products that differ from the cinnamon we buy in the shops. How we store and how long we keep cinnamon might also impact or degrade the active ingredients.

And consuming more isn’t going to provide additional benefit. In fact, it could increase your risk of side effects.

So if you enjoy the taste of cinnamon in your coffee, continue to add it, but given its strong taste, you’re likely to only want to add a little.

And no matter how much we’d like this to be true, we certainly won’t gain any fat-loss benefits by consuming cinnamon on doughnuts or in buns, due to their high kilojoule count.

Evangeline Mantzioris is Program Director of Nutrition and Food Sciences, Accredited Practising Dietitian, University of South Australia. This article is republished from The Conversation under a Creative Commons licence