Cross, who has lost 15kg in three months, said it focused on educating people about nutrition during four weekly group sessions. The challenge included body fat analysis, group support plus cash prizes.
Williden scored it: 7/10
"Research has shown social support is one of the key factors in helping to lose weight and successfully maintain weight loss."
2. Virtual gastric band
Cost: $100 a session. Four sessions recommended over six weeks.
Auckland hypnotherapist Avril Carpenter installs a "virtual gastric band" around the stomach using hypnosis to change attitudes and curb cravings.
"In the UK, they are conducting clinical trials with a view to having it endorsed by the National Health Service," Carpenter said. "It helps clients deal with cravings, lack of motivation to exercise, eating smaller portions, making smarter choices over a four to six week period, all without having to 'white-knuckle' it with willpower and gritted teeth."
Williden scored it: 4/10
"Hypnotherapy may be a useful tool to assist in weight loss when combined with nutrition and physical activity advice. However, there is not enough credible evidence to say that hypnotherapy will result in successful weight loss and maintenance of weight loss."
3. Body Trim
Cost: Free trial for 30 days with $19.95 postage and packaging. Return product if not successful or keep it for an extra $199.
The programme consists of three phases - detox, weight loss and weight maintenance .
The detox involves drinking 2-3 litres of water and eating six small protein meals for three days. Phase two adds a serving of fruit or carbohydrate at breakfast. The final phase allows two servings of fruit or carbohydrate and breakfast and lunch.
Thirty minutes of walking a day is advised but not strenuous exercise. Dieters can eat anything one day a week.
Williden scored this: 1/10
"A classic fad diet that relies on monotonous food choices, strict food regimes and rules, the elimination of whole food groups and just a nod to physical activity. A waste of time."
4. Slender Life
Cost: $270 for an 80-page booklet and a month's supply of homeopathic drops.
Director Karen Davison of Hamilton said the programme consisted of four phases, although the detox was optional.
The detox weaned people off wheat, dairy and sugars over two to three weeks followed by two days of fat loading to prepare the body for the "low-calorie diet".
The low-calorie diet involved eating about 700 calories a day from specific vegetables, fruit and meat. Clients also take homeopathic drops to release fat from fat cells.
Once clients reach a goal weight they can eat a greater variety of foods and increase their calorie intake.
Davidson said: "Most people who complete the programme find their tastes have changed, and now prefer to eat healthy whole foods from each food group. This programme is different. It requires you to put aside all previous ideas that you may have about diets."
Williden scored this: 1/10
"I'm not sure how eating just 700 calories, approximately 2900kJ, a day is going to suit anyone's lifestyle for an extended period of time."
