Physical Training Instructor Lance Corporal Paul Davis, right, takes members of the Combat Service Support Company 2/1 RNZIR for physical training at Burnham Military Camp, near Christchurch, on Friday.

The Defence Force has announced it will restrict sugary fizzy drinks and deep fried food as it emerges more than a quarter of its personnel are 'obese'.

"Make fitness your mission" was a recent New Zealand military recruitment slogan, but official figures show thousands of personnel are tipping the scales at obese or 'severely obese' levels.

The worst offenders are the Navy, with more than a quarter considered 'obese', followed by the Air Force, when measured against the Body Mass Index.

And although an army is said to march on its stomach, nearly one in five soldiers are considered obese, with a BMI index of 30-34.

One in ten Navy sailors are considered 'severely obese', with a Body Mass Index of over 35.

The figures covered all serving personnel for the past three years.

The Defence Force said it would introduce new nutritional standards from July 1 - and will ban fizzy drinks and restrict deep-fried food.

Defence Force dietitian Rebecca Smeele said that new minimum standards, which comply with World Health Organisation added sugar criteria, would ensure "the healthy choice is the easy choice".

The minimum standards required all bread to be wholegrain, restricted deep-fried menu items to two a week, and imposed a maximum sugar content on breakfast cereals.

Dieticians provided basic nutrition education for weight management as part of Defence Force health training and physical training.

Diets in the Defence Force had changed over the years, Smeele said.

"Years ago there used to be fizzy drink machines and soft-serve ice cream machines in the dining halls."

Soft drinks were banned under the strict criteria in the new minimum standards.

"When people drink their calories they can consume a lot more than if they're consuming real, whole food."

While minimum standards would be set for personnel eating at the military dining halls, Smeele said she could not control what people ate outside of the military environment.

For personnel not on initial military training it was discretionary whether they utilised the dining hall or brought their own lunch, or went off-site to get food.

Staff Sergeant Phil Stanbridge, who is responsible for personal training (PT) at Burnham Military Camp, said while there was formal training, personnel were responsible for their own fitness.

"Most units come into us for regular PT four times a week, so most of the time it's Monday, Tuesday, Thursday and Friday and we try and vary things up within a generalised scope of what we have been tasked to do."

Training sessions were compulsory for personnel, Stanbridge said.

Each year, every Defence Force member had to undertake a series of physical tests, and all personal training is undertaken with those tests in mind.

It was "reasonably common" that people would miss the grade.

"I wouldn't say it's a high number at all."

BMI - which measures a person's height-to-weight ratio - was not necessarily an indicator of health concerns, Smeele said.

One of the instructors at the Burnham gym was classed as being in the obese range, but was "one of the fittest individuals I have known," Stanbridge said.

For example, All Black captain Richie McCaw has a BMI of 30.

All Defence Force personnel had their BMI measured at each medical grading review, and at a minimum of five-yearly intervals.

Defence Minister Gerry Brownlee, would not comment on the obesity figures.

FITNESS TESTING: ARMY

Personnel have to pass an annual series of physical tests.

Required Fitness Level - minimum standard of fitness expected of all personnel in the New Zealand Army. Consists of a 2.4km run, press-ups and curl-ups, with the required standard adjusted for age and gender.

Land Combat Fitness Test - functional test that includes lifting and carrying. The final element is a 4km march carrying 20kg of kit including a rifle. Test not adjusted for gender or age

Basic Water Skills Test - personnel must swim 50m and tread water for three minutes.

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