Coffee is often seen as a guilt-free energy boost.
With less than one calorie per cup, it offers the same jolt as a chocolate bar.
It is also a bit of a darling in scientists’ eyes: even the American Heart Association said last year that the benefits of antioxidants in coffee and green tea are limitless.
But nutritional therapists warn there is one glaring side effect we may not realize: coffee could lead to weight gain, particularly belly fat.
Coffee could lead to weight gain, particularly belly fat, by raising cortisol levels
Tammy Lakatos-Shames, one half of the Nutrition Twins, insists that while she is not a coffee drinker (‘I just don’t like the taste!’), she usually sees it as a good thing for her clients – it encourages them to get up, be active, and triggers good mental performance.
However, she explains, its impact on hormones can be a silent fattener:
‘If you are someone that is more anxious it could increase body fat.
‘Caffeine does increase heart rate and it does increase respiratory rate. So for some people it does cause anxiety, it does cause jitters, and it does raise cortisol levels.
‘That causes body fat gain, especially around the middle.’
Cortisol is known as the ‘stress hormone’.
Normally, it’s present in the body at higher levels in the morning, and at its lowest at night.
Although stress isn’t the only reason that cortisol is secreted into the bloodstream, it has been termed the ‘stress hormone’ as it is released when the body is in ‘fight or flight’ mode.
This stress has been blamed for weight gain in women, particularly around the middle.
Ultimately, Lakatos-Shames says, the biggest issue with coffee for weight-watchers is that there’s a culture of adding fattening products.
‘As a registered dietitian, you do think of coffee leading to body fat gain because of the things we add to it. We ask clients: “do you drink it with cream? How many do you have a day? Do you have it with sugar?” Those are the real issues.
‘From a nutrition perspective, most people who just drink black coffee are fine.
‘The issue is more about whether people who drink coffee take it with cream and a donut, or with sugar.’
When it comes to keeping cortisol levels in check, she says, it’s about finding your personal limit of caffeine per day.
‘Some of us are fast caffeine processors.
‘Most people when they get too jittery they cut back on the coffee, and that’s a good idea – work out what works for you.
‘For some people, anything more than an 8oz cup can make them jittery, so try just limiting yourself to a 4oz cup.
‘Be aware that Starbucks, for example, has stronger coffee, so one 12oz cup is about 200mg, while other coffee may be weaker per cup.’
She adds: ‘People who have heart disease or strokes in their family should have no more than 200mg of caffeine a day.’