The drinks are on you ... literally

Veronica Merkel enjoys lunch on Princes Wharf with a friend. Photo / Janna Dixon

It's Christmas party time and Veronica Merkel enjoys the occasional long-lunch on Auckland's Princes Wharf.

But she knows what a glass of wine or two will do to her diet. Her glass of wine has 715kj in it, and to get that off the waistline you need to go for 34 minutes of brisk walking.

"If I'm at a function," Merkel says, "I'll usually have a splash of wine with sparkling mineral water. That way no one notices you aren't drinking, and if you add a sprig of mint it can be really refreshing,"

Healthy Food Guide nutritionist Claire Turnbull said an extra three drinks a day over two weeks would roughly translate into a kilogram of weight gain.

A 330ml bottle of beer has 1015kj and will take 48 minutes to walk off, a light beer 400kj (19 minutes), 75ml cosmopolitan cocktail, 710kj (43 minutes), and a 300ml single vodka and soda water, 265kj (8 minutes).

Even tonic water contains 529kj and will take 25 minutes to burn off.

But there are ways to enjoy the silly season without falling off the diet wagon, says Turnbull. Tall glasses tend to trick the brain into drinking slower, lessening the number of calories consumed.

"There's something about short, fat glasses that makes people knock back their drinks," she said.

Vodka, soda and fresh lime is the best drink for people watching their weight.

Jenny Craig's regional manager, Natalie Russell, said the festive spirit made people more generous with how much they poured into glasses.

A standard bottle of wine should stretch over 7.5 drinks with just 100ml in each serve, she said.

"Most people would pour at least 200ml into a wine glass, double what is recommended. By the time you have three generously poured glasses of wine you may as well have had two dinners, in terms of calorie intake."