There’s a lot of buzz around green coffee bean extract which has been praised as a miracle fat burner – but is there any evidence green coffee beans can actually help you lose weight?
It turns out that at least 110 research papers have studied the weight loss benefits of green coffee and the evidence appears to stack up. You might think the fat burning effects of green coffee beans are due to the caffeine, and this is partly correct. But the ‘magic’ weight loss ingredient in green coffee beans are its rich content of antioxidants known as chlorogenic acids, which means that decaffeinated green coffee beans are effective for weight loss, too.
How green coffee bean extracts boost weight loss
Chlorogenic acids are powerful activators of a gene called SIRT1 which, when switched on, increases your metabolic rate, increases the breakdown of stored fat and boosts fat burning. One of the ways green coffee extracts work as a fat burner is by causing you to ‘waste’ more energy as heat which speeds the weight loss process. Chlorogenic acids also improve the regulation of blood sugar levels by reducing glucose absorption in the small intestine and reducing the production of glucose in the liver, and increasing the release of gut hormones which signal you are full. The combined result is to reduce hunger and snack attacks. The full way in which coffee (and tea) work to boost weight loss is still under investigation, but researchers recently stated that they may offer a potential new strategy to prevent or treat obesity.
Roast coffee beans don’t work
Unfortunately, you can’t just drink a cup of espresso to get the same weight loss boost. Yes, roast coffee provides a shed load of caffeine, and that can speed your weight loss, but roasting will remove the additional benefits of the chlorogenic acids – their levels are halved after a 12 minute roast and disappear entirely after a 20 minute roast. That means you have to take your coffee beans raw, or green, if you want to maximise your weight loss. Coffee made with green beans doesn’t taste that brilliant – we know, we’ve tried – but luckily green coffee extracts are available to support your weight loss program.
Green coffee and weight loss
Most of the studies looking at green coffee bean extracts for weight loss are small, but they show exciting results given that taking the coffee bean extracts was the only change made by those taking part.
The results from three clinical trials, involving 142 people who wanted to lose weight showed that taking green coffee bean extracts (150 mg to 200 mg per day) for between 4 and 12 weeks, increased total weight loss by 2.47 kg (5.5 lb) compared with placebo pills.
In one study, involving 30 people who wanted to lose weight, those given a coffee drink enriched with green coffee chlorogenic acid, lost 5.4kg over 12 weeks compared with just 1.7kg for those drinking coffee without the green coffee extracts.
What to look for in a green coffee bean extract
Green coffee beans come in two main varieties: Arabica coffee beans, which account for three-quarters of the coffee grown as they are more aromatic, and Robusta coffee beans which as their name suggests have a more robust, bitter flavour. Robusta beans contain almost twice as much caffeine as Arabica beans (2.7% versus 1.5%) and twice the concentration of chlorogenic acids (10% versus 5%). Most green coffee bean extracts therefore contain concentrated extracts from Robusta beans.
NB Some unregulated green coffee slimming products have been found to contain a prescription-only drug, sibutramine. Look for products made to GMP (pharmaceutical) standards which ensures they are checked at every stage of processing for purity.