10/07/2014 13:03 BST | Updated 09/09/2014 06:59 BST

How to Drink and Avoid Gaining Weight This Summer

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We are smack bang in the middle of summer, and everyone is trying to keep fit and keep their bikini bodies, while also joining in on all the summer festivities. As a health professional I strongly believe in the saying 'everything in moderation', and believe that to be healthy you need to enjoy good food and good company. Many people take the 'all or nothing approach' to keeping fit and believe if they don't cut out alcohol then what's the point? But you have to remember, summer isn't all about the beach, its three months of parties, barbecues in the park and rooftop bars. Who would want to have to say no to that enticing jug of Pimm's every Sunday?!

I'm here to tell you that you can enjoy summer including those few drinks at the rooftop bars and keep fit. All you need to do is understand what you're consuming.

The key to weight loss is energy in must be less then energy out. That is you must move more and eat less. The energy that you don't use is stored as fat in your body. Alcohol is empty calories. Unlike fat, carbohydrates and protein, alcohol has no nutritional value e.g. gives us no useful nutrients, but is energy dense. Basically the higher the alcohol content of your drink the higher the energy content. If your drink has added sugar say for example from juice or soft drink, it has an even higher energy content.

When considering how much energy your favourite alcoholic drink has, I convert it to your standard slice of bread. You average pint of lager (5% alcohol) and your favourite glass of red wine has the same amount of energy as two slices of bread.

Some other favourite alcoholic drinks:

Pint of cider = 2 ¼ slices of bread

Pint of light beer (2.7%) = 1 ½ slices of bread

Smirnoff Double Black = 2 ¾ slices of bread

Gin/Vodka and Tonic = 1 ¼ slices of bread

Glass of Pimm's = 1 ½ slices of bread

In a night out if you drink two glasses of 250ml red wine or two pints of lager you are getting the equivalent of four slices of bread. If you are out drinking with a three course meal that is energy on top of whatever you have already eaten. A night out with your friends drinking Smirrnoff Double Blacks, could give you same amount of energy as half a loaf of bread (four Smirnoff's is the equivalent to 11 slices of bread!!). The way I like to think about it is, you wouldn't sit down with a three course meal and eat an extra four slices of bread. Also in the same way, if you were on a night out you wouldn't eat 11 slices of bread.

I am not saying that you have to cut out alcohol all together. You just need to include the energy that you get from alcoholic drinks into your daily intake. For example instead of having a glass of beer with your two baked potatoes, steak and vegetables for dinner tonight, cut it down to one baked potato and increase your serving of vegetables (so you won't be starving). Or instead of having a glass of red wine with you spaghetti bolognaise tonight, halve your serving of pasta and add some steamed green vegetables.

Another tip is to try for low alcohol options. One pint of light beer (2.7%) has 118 calories, equivalent to one ½ slices of bread. When compared to a pint of lager (5% alcohol), it provides 190 calories or two slices of bread. In a night if you have four beers, choosing light beer saves you consuming the energy equivalent to bread for a sandwich.

Also another option is mixing drinks with diet soft drinks or soda water. A standard gin and tonic provides 110 calories, that's equivalent energy to one ¼ slices of bread. If you mix your gin with diet tonic it provides only 70 calories (equivalent to ¾ slice of bread). Almost halving the calorie intake!!

Some other easy ways to reduce your energy intake from alcohol, without feeling like you are missing out include:

•Opting for wine spritzers or shandies with diet lemonade. This will reduce the alcohol intake and in turn energy intake of the drink.

•Set yourself a 'drinks limit'. Before you go out, prepare yourself and set the amount of drinks (slices of bread) you plan to have.

•Drink a glass of water in between each alcoholic drink. Often, in particular on a hot summer day, our thirst for water is masked by our 'thirst' for alcohol. I know sometimes if I am thirsty and head to a barbeque, as soon as I know it I have gone through two ciders in the space of an hour. Keeping hydrated while drinking stops you over drinking and in turn consuming too many calories from alcohol.

Summer is all about enjoying yourself, making the most of those long warm days. Just being aware of what you are consuming, can help you avoid that summer blow out.