A diet can last a lifetime only if it involves eating good food that also tastes good.
Diet trends come and go because the eating habits can't possibly be maintained for more than a few weeks at a time when you consider people's busy lifestyles, dining out and family meals.
Not everyone can go every day without cake or carbohydrates.
So dietitian Shamala Ratnesar went about developing the Total Life Diet, which is a nutrition, health and weight loss program.
"I wanted a healthy diet to follow for the rest of my life," says Ratnesar, who admits to trying numerous diets as a teenager.
Ratnesar, whose studies included two years at the University of Wollongong, has had years of experience working in the public hospital system and in private practice.
She has developed the program based on real science and says that food quantities are one of the most important considerations for losing weight and controlling blood glucose levels.
"People need to know how to eat over an entire day," Ratnesar says.
"I'm really keen to clear the confusion," she adds, saying that it's fine to eat carbohydrates and sugar in the right amounts.
Ratnesar says the secret formula to losing weight, maximising energy levels, controlling blood glucose levels and staying healthy is two to three serves of carbohydrate foods at meals and one to two serves as snacks. And protein and omega-3s are important too.
"At some meals, people eat too many carbs and in others they eat too little - it's about eating a steady amount," she says.
The Total Life Diet book also includes 80 meal plans and 170 recipes (including cakes), that Ratnesar has "tried and tasted" over the years, with some help from her mother.
Her favourite meals include Atlantic salmon, prawns and omega-3 eggs.
Ratnesar is also an advocate for omega-3s, having already published two books about the benefits of the fatty acids.
Her latest book also includes information on how to live healthy with diabetes, how to read labels on packaged foods ("people look at the nutrition panel but don't read the ingredients - and light doesn't mean low-fat"), and tips for eating out and motivation.
Overall, the emphasis is on eating more variety in less quantities.
"People I see are shocked they can eat rice and bread - it's the quantity that matters," Ratnesar says.
Ratnesar adds that men can follow her diet too. "It's not any harder for men," she says.