Low-carb and high protein diets aren’t always healthy.
Interest in weight-loss diets as a way to combat obesity is growing. And with obesity a growing health problem in Singapore, it would help to know if such diets can be used to combat this rising trend.
People who are obese are at a higher risk for cardiovascular disease, such as heart problems, as well as type 2 diabetes.
They are also more prone to the metabolic syndrome, which refers to conditions such as higher blood pressure or blood sugar, excess body fat around the waist and abnormal cholesterol levels.
In Singapore, obesity rates increased from 6.9 per cent in 2004 to 10.8 per cent in 2010. Correspondingly, the diabetes rate has gone up from 8.2 per cent in 2004 to 11.3 per cent in 2010.
LOW CARB OR LOW FAT?
Many studies have explored the dichotomy of a low-carbohydrate diet versus one that is low in fat.
In 2003, two studies published in the prestigious New England Journal Of Medicine found that obese patients on a low-carb diet lost more weight – about 5kg to 6kg – than those on a low-fat diet, who shed about 2kg to 3kg.
Those on a low-carb diet also saw a drop in their blood triglyceride and had elevated good cholesterol levels – more so than the group on a low-fat diet.
Both diets helped to lower the patients’ diastolic blood pressure significantly and reduced their tendency to be diabetic.
Although the low-carb diet looks more promising, the drop-out rate was very high, which meant that long-term adherence is a problem. There is also concern that the increased fat and protein intake may be bad for the heart.
More recently, a 2012 study by the University of Athens Medical School found that eating 920g less carbohydrate and 5g more protein per day may be bad for the heart.
The study, which tracked 43,496 Swedish patients for close to 16 years, found that those dietary changes led to a 5 per cent higher risk for coronary heart disease. The data was surprising as it was expected that a low-carb diet would reduce the likelihood of heart disease.
The answer may lie in a study by the Harvard School of Public Health, published in 2010 in the Annals Of Internal Medicine.
It involved the data of more than 120,000 people in the United States, who were followed up for more than 20 years. Its findings show that the type of protein in a low-carb diet makes a difference.
Animal protein refers to products such as meat and eggs, while vegetable protein can be found in soya beans and greens like broccoli. The group who mainly ate animal protein had an increased risk of chronic diseases and death. They were more likely to die from heart disease and cancer than those who mainly ate vegetable protein.
In fact, there was a protective effect for those who ate vegetable protein. They had a 20 per cent drop in deaths in general, including 23 per cent fewer deaths from heart disease.