You’ve cut back on crisps, curtailed your favourite chocolate indulgence and banished the biscuit barrel only to find that your weight is still creeping up. Surely it’s your “big bones” or metabolism that’s to blame. The truth, however, may be much simpler, if harder to swallow. A recent report in the Journal of the American Dietetic Association reveals that nonalcoholic beverages make up 22 per cent of US calories and supply half of the added sugar consumed by its citizens.

Where America leads, we tend to follow. Your own personal drinks audit could be both revealing and surprising, and you may just find that your upwardly mobile weight has at its source a glut of liquid calories we unwittingly consume.

Take a hypothetical day. You start with the little probiotic yoghurt shot, which starts the liquid calorie clock ticking by notching up 77. Then there is the medium-size latte you grab on the way back from the school run or on the way to work: another 265. Perhaps you have a fruit smoothie thinking that it is a good way to get one of your “five a day”. Allow another 130 calories per 250ml bottle for this drink. Next comes lunchtime and a can of Coke, with 205 calories, then a mid-afternoon hot chocolate to keep you going. Expect 448 calories for a medium-size serving from a typical coffee shop.

Once you get home you may enjoy a glass of seemingly healthy cranberry juice, a sparkling elderflower cordial drink or a Duchy Originals Organic Fruit Refresher with dinner instead of wine, all with 120 calories per average 300ml tumbler. Then to round off the day, a nice warming malty bedtime drink, with 188 calories for a small mug. While few of us would consume all of these in one day, you get the picture. Were someone actually to drink this lot, the calories would top 1,432; more than 70 per cent of an average woman’s daily needs of 2,000 and over half a man’s daily requirements.

The reality is that many drinks are delivering the same number of calories as a fairly substantial snack if not, in the case of hot chocolate, a main course. For 450 calories you could tuck into a medium-sized portion of spaghetti bolognaise.

That said, according to researchers from around the world, liquid calories don’t fill us up in the same way as food. Jeya Henry, professor of Nutrition at Oxford Brookes University, says: “Tests show that people don’t get the same satiation from calories in drinks as they do when eaten in food.”

He believes there may be a good biological reason why we don’t detect these liquid calories from an evolutionary point of view.

“Dehydration was the biggest killer when man evolved in the savannah regions. Fluids rehydrate, whatever their calorie content, and man had to drink whatever was available, whether it was calorie-free water or calorie-rich coconut milk. The last thing you wanted was human beings putting the brakes on drinking. The idea that liquid calories do not feed back into the satiety centres in our brains makes evolutionary sense.”

As Professor Henry points out, the problem is that evolution is out of sync with modern life and sociology. “In those days we would have burnt off extra calories consumed, for instance, from coconut milk. Nowadays, with sedentary lifestyles, this is not automatically happening.” How many of us, for example, would hand our children a 500ml bottle of Frijj Strawberry Flavoured Shake in place of dinner, even though, with 320 calories, it has 30 more calories than two grilled fish fingers, a scoop of mashed potato and a serving of baked beans?

No one is saying we should give up soft drinks. They can be immensely enjoyable and thirst-quenching. A glass of fruit juice or a smoothie counts towards one of our portions for the day. But don’t drink five glasses and think that’s your fruit and veg for the day. However many glasses of juice you drink counts only as one portion because you lose vitamins in commercially made smoothies, and juice made from concentrates lacks the nutrients found in fibre.

Milk-based soft drinks can also be good, full of calcium and protein. But if you include these drinks in your diet, it is important to tot up the calories before you slurp them down, and make the appropriate allowance elsewhere in your daily calorie intake.

However, there is an advantage to buying drinks in the kind of single servings mentioned above. They tend to limit your intake to that serving size. The problem with buying drinks in one-litre cartons or bottles is that, as research indicates, the larger the portion, the more we are likely to consume. This holds true for food as well as drinks. In clinical research, when women were asked to cook a meal for two, they used over 100ml of sauce for a chicken dinner from a 900ml bottle but only 75ml when given a 450ml bottle.

Equally, research published in the Journal of the American Dietetic Associationlast December showed that when offered a fizzy drink in a 360g serving people took a smaller quantity (giving them 128 calories per glass), compared with 151 calories worth of drink when offered it in a 540g serving.

The moral of the story is to keep a close check when pouring from litre cartons. Few of us will serve ourselves the equivalent of the 200ml found in an individual Tetra Pak carton of fruit juice, but it is worth bearing in mind that for every 100ml extra you pour from a large carton, you need to add 50 calories to your daily total.

Pure fruit juices, however, are not such a problem as other more calorie-dense drinks. A 500ml bottle of Coca Cola contains 210 calories, the equivalent of breakfast or a light lunch,such as two poached eggs and grilled mushrooms on toast for breakfast or a tuna salad wrap for lunch.

But soft drinks do not just give us calories. “Energy” drinks also provide significant quantities of caffeine. Red Bull, for instance, has about the same amount of caffeine as a cup of coffee. Given that experts recommend we stick to five to six cups of caffeinated drinks a day, energy drinks should be included in your daily caffeine as well as calorie total. “Juice drinks”, unlike pure fruit juice, which is just the juice, can contain artificial sweeteners, flavourings and colourings and added sugar in various forms such as glucose-fructose syrup.

This is rapidly absorbed and is best avoided when following a low-GI diet to avoid big blood sugar highs and lows.

With vegetable juices, it is also worth noting the amount of salt they provide. V8 100% Vegetable Juice, for instance, gives us 0.6g per 100ml. In a small 200ml glass, this means that you are getting a fifth of your daily salt in drink form. It is wise to account for this when working out salt intakes (adults should not exceed 6g a day; children aged 7-10, 5g a day, and aged 4-6, 3g daily).

This brings us back to the old adage — everything in moderation. Follow this advice and whether you fancy the odd cola, coffee, hot chocolate or vegetable juice, if you allow for the calories and don’t overdo them, there is no need to give them up completely.

It is always worth remembering, however, that if you just want to quench your thirst, tap water is safe, cheap and calorie-free.

The healthy way to quench your thirst

Here are some good choices from Amanda Ursell

Ocean Spray Cranberry Classic Light
60 calories per 250ml
Good because research indicates that cranberries contain the supernutrient proanthocyanidins (PACS). When drunk daily, these appear to help stop the E. coli bacteria that cause cystitis from grabbing on to the urinary tract walls by creating a kind of nonstick coating. By sliding out of the body before they have a chance to set up an infection, PACs potentially help to stop an outbreak. Test-tube studies also suggest that they may be useful in reducing the activity of H. pylori, the bacteria that trigger stomach ulcers. This juice contains sweeteners and glucose-fructose syrup, but totally unsweetened cranberry juice is undrinkable and at least this has less sugar than the original versions.

Cawston Vale Pressed Apple and Ginger Fruit Juice
44 calories per 100ml
Good because new research from Glasgow University has indicated that there are particularly good levels of the antioxidant supernutrients known as polyphenols in cloudy apple juice. These, the researchers say, are lacking in citrus-only drinks such as orange juice and are believed to play a role in protecting against chronic diseases such as cancer when eaten in whole fruits, as well as reducing cholesterol and improving circulation. The ginger in the juice may help to curb travel sickness and nausea associated with early pregnancy.

Tropicana Calcium
107 calories per 250ml
Good because this pure orange juice base has had calcium added so that a 250ml glass provides 305mg of this essential bone-strengthening mineral. It is a particularly good way of getting calcium into teens who do not drink much milk. 305mg is just under half a teenage girl’s 800mg daily requirement and almost a third of a teenage boy’s 1,000mg target. Adult women and men need to have 700mg daily.

Lipton Ice Tea
63 calories per 250ml
Good because it has no artificial sweeteners, colourings or preservatives and has 35 per cent less sugar than most soft drinks. It also supplies some of the antioxidants present in tea, which have been linked to protecting our circulation. The flavoured versions, including lemon, peach and mango, have the same sugar content and calories.

Skinny Decaffeinated Cappuccino
77 calories per “regular” 350ml cup
Good because the skimmed milk gives us calcium and protein and, according to experts at Pennsylvania State College of Medicine, milk turns to a semi solid in our stomachs so it requires some digesting. This sends signals to our brains that milk-based drinks have a slightly satiating effect. Research also indicates that a cappuccino will fill you up more than a latte because its froth makes it look bigger. By opting for decaffeinated, you are not adding extra caffeine to your daily total.

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