Carrying out a strict diet low on carbohydrates but high on fat in just eight weeks can lead to health complications and rapid weight gain, a new study revealed.
This surprising finding has prompted diabetes experts from the University of Melbourne to issue a warning about these so-called fad diets as their efficacy supposedly has little or no scientific evidence.
Sof Andrikopoulos, lead author of the study and an associate professor at the university, said this type of diet, such as the famous Paleo diet, is not recommended especially for people who already lead sedentary lifestyles and are overweight.
The hype on these diets – driven by celebrity chefs in particular as well as celebrity weight loss stories in tabloid media and reality TV shows – are causing more people to try fad diets, he said.
Additionally, the low-carb, high-fat diet is significantly risky for people with pre-diabetes or diabetes, Andrikopoulos said.
"Low-carbohydrate, high-fat diets are becoming more popular, but there is no scientific evidence that these diets work," said Andrikopoulos, who is also the president of the Australian Diabetes Society. "In fact, if you put an inactive individual on this type of diet, the chances are that person will gain weight."
Testing The Theory On Mice
Andrikopoulos and his colleagues originally sought to test whether low-carb and high-fat foodstuffs would be beneficial to the health of people with pre-diabetes.
First, the team divided several mice with pre-diabetes symptoms into two groups. One group was put on the low-carb, high-fat diet which had 60 percent fat and 20 percent less carbs than their typical diet. The other group ate their usual diet that contained 3 percent fat.
The Paleo diet group gained more weight after eight weeks. Their bodies' intolerance for glucose turned worse and their levels of insulin elevated. They gained 15 percent of their weight, and their fat mass increased from 2 percent to nearly 4 percent.
"To put that in perspective, for a 100 kilogram person, that's the equivalent of 15 kilograms in two months," said Andrikopoulos. "That's extreme weight gain."
He said the level of weight gain will elevate a person's blood pressure and his risk of depression and anxiety. It may also cause arthritis and bone issues.
For a person who is already overweight, the Paleo diet will further increase levels of blood sugar and insulin, consequently developing to diabetes.
Too Much Fat Is Not Good For Your Health
Andrikopoulos said their model tried to mimic the Paleo diet's supposed benefits, but they didn't see any improvements in weight. He said the bottom line is that eating too much fat is not good for the health.
Meanwhile, Andrikopoulos said the Mediterranean diet, being backed by evidence, is recommended for people with pre-diabetes or diabetes. He also said this type of diet is a low-refined sugar diet that contains healthy oils and fats from extra virgin olive oil, fish, protein and legumes.
In the end, the associate professor said there is an important public health message in their study.
"You need to be very careful with fad diets," added Andrikopoulos. "Always seek professional advice for weight management and always aim for diets backed by evidence."
The findings are featured in the journal Nature.