A number of studies suggest that full-fat milk drinkers tend to be slimmer than those who drink skimmed, or swerve dairy altogether.
When Bob Dylan pleaded for “one more cup of coffee for the road”, the bedraggled bard probably had more poetic things on his mind than his jeans size. Still, a new study from Imperial College London suggests a happy by-product of his java obsession.
Higher blood-caffeine levels could help people stay slim, it seems. But how? And can any other drinks claim – with any scientific validity – to do the same? Should we all aim for one more cup of green tea, apple-cider vinegar, or even milk?
While there’s no single magic bullet for weight loss, experts suggest there are certain drinks that could contribute to a slimmer waistline and boost your metabolism – when combined with a balanced diet.
Imperial’s study investigated whether caffeine consumption could cause weight loss and thus reduce the future risk of type 2 diabetes. The results?
“The caffeine consumed in approximately four cups of coffee can increase your metabolic rate by 3-11 per cent,” says Dr Stephen Lawrence, associate clinical professor at the University of Warwick’s medical school, who was not involved in the research.
The higher your metabolic rate, the easier it is for you to burn fat, he explains, so the implication is that: “If you consume several cups of coffee, your body will burn fat at a greater rate than those who do not consume coffee.”
Pause, however, before racing for the Nespresso machine. The study, says Dr Lawrence, suggests correlation, not causation. Plus, coffee is often drunk with milk and even a Hobnob or two. So, overall: “The science suggests relatively good evidence that consuming caffeine increases fat burning, even at rest; however, it does not constitute a treatment for obesity and, used wrongly, may result in weight gain or even harm.”
The hard truth? “There is a far greater body of good-quality evidence showing that the traditional methods for weight loss – reducing calorie intake and increasing physical activity – represent the safest and most effective way of losing weight.”
“Green tea contains the catechin epigallocatechin-3-gallate (ECGC), a powerful antioxidant that helps to reduce inflammation and prevent cell damage, and which may also promote weight loss,” says nutritional therapist Lucy Miller.
In fact, “studies have shown that green tea has thermogenic properties and promotes fat oxidation beyond that explained simply by its caffeine content”.
Miller points to a Japanese study showing tea consumption is also associated with a 42 per cent reduction in the risk of type 2 diabetes.
Another small 2005 study found that overweight people who consumed 150 milligrams of caffeine and green tea for three months saw a significant reduction in stubborn belly fat and waist circumference.
And matcha? “It comes from the same plant, Camellia sinensis, although the teas are grown and prepared slightly differently. Matcha tea generally contains more catechin antioxidants, so it may be an even better choice.”
If your morning brew is more likely to be a mug of builder’s, there is hope for you, too. In 2017, researchers from UCLA, in the US, demonstrated for the first time that black tea may also promote a healthy weight.
“It was known that green tea polyphenols are more effective and offer more health benefits than black tea polyphenols, since green tea chemicals are absorbed into the blood and tissue,” said Susanne Henning, the study’s lead author. “Our findings suggest that black tea, through a specific mechanism through the gut microbiome, may also contribute to good health and weight loss in humans.”
Her research indicates that these benefits are brought about by changes in the gut bacteria: “Our findings suggest both green and black teas are prebiotics, substances that induce the growth of good microorganisms that contribute to a person’s wellbeing,” she said. “For black-tea lovers, there may be a new reason to keep drinking it.”
The catch? The study administered tea extracts to mice, not men. And there was no control in which the mice added four spoons of sugar.
“Studies have shown that consuming apple-cider vinegar before eating can be effective in reducing postprandial glucose and insulin levels, both of which are fundamental in weight management,” says Miller. “It also supports the production of stomach acid, which will help aid digestion.”
There’s more: “Unfiltered apple-cider vinegar contains strands of enzymes, proteins and healthy bacteria that can support a healthy gut. A healthy gut microbiome is essential for the metabolic process, which in turn helps with weight loss.”
There is some evidence to suggest that apple-cider vinegar can reduce appetite by slowing the rate that food leaves the stomach, so you are less likely to reach for snacks and extra calories. Want to give it a whirl? Miller suggests stirring a shot into warm water before meals.
Skimmed milk has less than two-thirds of the calories of full-fat milk, so it must be less fattening, right?
Well, no, actually. A number of studies suggest that full-fat-milk drinkers tend to be slimmer than those who drink skimmed, or swerve dairy altogether.
One, published in The American Journal of Clinical Nutrition in 2010, found that trial participants who ate or drank the highest amount of dairy lost about 12lb (5.4kg) at the end of the two-year study, compared with those who consumed the least, who lost 7lb (they had also been following either a low-fat, low-carb, or Mediterranean diet).
“Our study suggests that both higher dairy calcium intake and increased blood vitamin D are related to greater diet-induced weight loss,” conclude the researchers. It could also be that drinking full-fat milk reduces your appetite, leaving you less likely to snack.
Last summer, researchers from Newcastle University found that downing a couple of shots of whey protein before meals might help people with diabetes control their blood-sugar levels.
“Several studies have suggested that higher protein diets may increase total weight loss and percentage of fat loss,” says Miller. But beware off-the-shelf protein shakes, which can be loaded with sugar and calories. Miller suggests making your own smoothie: “Focusing on green vegetables, a small amount of ‘good fats’ and adding a scoop of protein powder to ensure plenty of antioxidants, fibre and protein, will help stabilise blood sugar and keep you feeling fuller for longer.”
Nor are all protein powders created equal. “I’d go for a clean pea protein from Nuzest, or organic, grass-fed whey protein from Garden of Life,” says Miller.
Her recipe is as follows: “A base of coconut water (no added sugar), a large handful of kale or spinach, fresh ginger, a small amount of nut butter, frozen wild blueberries and a scoop of protein powder.”
This might be difficult to swallow, but “no single drink or food is going to be a magic bullet for weight loss”, says Dr Emily Leeming, senior nutrition scientist at Zoe, a research programme based at King’s College London. “Certainly, too many sweet fizzy drinks, cordials and fruit juices will give you extra, mostly empty calories, and that isn’t helpful when you’re trying to lose weight,” she says.
“Weight loss is incredibly complex and, as scientists, there’s still a huge amount we don’t know about how to effectively lose weight and, importantly, keep it off. Having a healthy overall diet and lifestyle is the best way to look after your health and to help you reach your healthiest weight.”
How restaurants are feeding a city's obsession with eating the next big thing.