The facts on dieting

Jul 17 2006

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.

Research has also revealed that people who follow a vegetarian diet usually eat fewer calories and less fat and have lower body weight relative to their heights than non-vegetarians; but becoming vegetarian is not a guarantee of weight loss, especially if high-fat, high-calorie foods with little or no nutritional value form a part of your daily meal choices.

Herbal weight loss products have not been tested scientifically to prove that they are safe or that they work.

Also, some products may be unsafe if used with other medication or may be risky in people with certain medical conditions.

Dieting alone can help you lose weight but if you add exercise to dieting, you can double your rate of weight loss.

Experts recommend at least 30 minutes of moderate-intensity physical activity on most, if not all, days of the week.

There are some diet drugs that have been approved by health authorities to help people lose weight, but they are specifically aimed at those who are medically obese or have obesity related diseases such as diabetes or high blood pressure and should only be used under medical supervision, because they cause side-effects.

There is no evidence that diets proclaiming to reduce fat in particular body areas actually work and only exercise combined with a diet will help tone up in specific areas.

Many meal replacements shakes or bars lack fibre and phytochemicals that aid in disease prevention and should only be used for a short time and balanced meals that which provide sufficient calories, protein, fibre and phytochemicals should be eaten for the rest of the day.

The diet Eat Right 4 Your Type refers to blood type and the claim that each blood type has its own unique antigen marker that reacts negatively to certain foods, has no scientific basis.

Eliminating whole food groups, may cause certain nutrient deficiencies, excluding dairy products for example may result in calcium deficiency.

In conclusion the researchers found that all the studies completed so far have found that diets do not help individuals to change their long-term eating habits, and so most commonly, weight is re-gained once old eating habits resume.

Most experts agree that a healthy diet is one with plenty of fresh fruit and vegetables and fish, lean meat and pulses, and low on salt and saturated fats.