According to researchers from Tufts University in the U.S. when overweight or obese individuals were placed on currently popular diets such as Atkins, Ornish, Weight Watchers and Zone diet, after one year, most who stuck to the regime lost weight and all four diets worked equally well.
It appears however that the old adage eat less and exercise more may not be the definitive answer to obesity and other factors may be at work such as a lack of sleep, modern medications, heating and air conditioning, genes, giving up smoking, birth weight, and aging.
Scientists from Yale, Cornell and Johns Hopkins say there is only 'circumstantial' evidence supporting poor diet and lack of exercise as the main causes of obesity.
Recent research does go a long way to dispel many of the myths associated with dieting and comes up with some sound advice.
They say completely eliminating treat foods leaves dieters feeling deprived, demotivated and can lead to intense cravings and binge eating later in the day, and an occasional planned indulgence without feeling guilty, is fine as long as the planned balanced diet is resumed.
Drinking green tea without milk or sugar is a healthy option but has little effect on the fat burning process and weight loss.
Detox diets can be highly motivating in the early stages of weight loss but excess weight is due to deposition of fat and not because of build up of toxins and detox programs are only recommended for a few days.
Fat metabolisers that theoretically raise metabolism and help burn body fat are not based on sound clinical evidence and there are serious concerns about the health risks associated with some such products which have been linked to high blood pressure, severe headaches, heart rate abnormalities, seizures, heart attacks and even deaths in some susceptible individuals.
High-protein/low-carbohydrate diets usually include generous amounts of beef, pork, chicken, eggs and butter and limits foods high in carbohydrates such grains, beans, fruits, breads, rice, potatoes, pastas and starchy vegetables.
They are based on the theory that when you lower carbohydrate intake, the body burns its reserves of stored carbohydrate (glycogen) and fat for energy.
A lot of weight is lost however because of water loss and the resulting raised ketones levels in the bloodstream suppress appetite, cause dehydration, headaches, nausea, tiredness, weakness and bad breath.
As the diet strictly limits intake of whole grains, fruits and vegetables key nutrients like B vitamins, phytochemicals and dietary fibre that can protect you from chronic diseases are missing from the diet.
Concerns have also been voiced over the long-term effect of such diets on the build-up of fatty deposits in blood vessels, uric acid levels which increase likelihood of developing gout, and the effect on calcium stores in bone.
Despite recent scientific theories about carbohydrates and insulin levels there is little scientific evidence to support the claim that carbohydrates are fattening.
That only low-fat foods should be consumed for weight loss is also questionable as often extra sugar, flour or starch may be added to these foods to improve flavour and texture after fat is removed and these ingredients can add back calories.
Skipping a meal is also not the answer as research has found that the ploy only serves to increases the likelihood of an eating binge later on in the day.
Breakfast is apparently the most common meal missed, but a recent Harvard study has found that those who ate breakfast regularly were less likely to become obese, compared to those who skipped it.