30 March 2015
Eating low carb? Get your facts straight – your life depends on it!
So your personal trainer, the latest weight-loss book you picked up, and even your next-door neighbour are all telling you that if you want to lose weight and get healthy, you have to ditch those evil carbs and eat more protein (and they ALWAYS mean animal protein). But is this advice really backed up by any hard science? The results of a study published in the Annals of Internal Medicine (1) have shed light on this critically important subject, and the message could not be more stark: eat the wrong kind of low-carb diet, and you have a higher risk of dying, especially from cancer.
What’s impressive about this study is the sheer scale of it: over 85 000 women (aged between 34 and 59 when the study began) who were enrolled in the Nurses’ Health Study, were followed up for 26 years. More than 44 500 men (aged 40 to 75 at baseline) enrolled in the Health Professionals’ Follow-up Study were followed up for 20 years. All participants were initially free of heart disease, cancer and diabetes.
The study participants completed dietary questionnaires every 4 years throughout the course of the follow-up period. In evaluating these data, the researchers focused on the proportion of fat, carbohydrate and protein in the diet – and crucially, whether these nutrients were derived primarily from animal or plant sources.
Here’s what they found:
Participants with a low carbohydrate intake and a diet heavy in animal-based foods had:
- a 23% higher all-cause mortality rate (risk of dying from any cause);
- a 14% higher risk of dying from heart disease; and
- a 28% higher risk of dying from cancer.
And on top of all this, they were heavier than higher-carb eaters!
Participants with a low carbohydrate intake and a diet heavy in plant-based foods (primarily vegetables) had:
- a 20% lower all-cause mortality rate; and
- a 23% lower risk of dying from heart disease.
Those touting high-animal protein diets for weight loss and health improvement (including our own CSIRO with its Orwellianly-titled Total Wellbeing Diet) need to take a good, hard look at this study, and then ask themselves if they can, in all conscience, continue to promote a diet-style that increases people’s risk of getting cancer and dying.
As for those people currently following a low-carb diet, I would urge you to place high-protein, low-carb vegetables at the centre of your eating plan, and keep the animal protein to a minimum.
As the lead researcher in this study, Dr Theresa Fung, said,
“This research indicates that all low carb diets are not the same, and the differences have an indelible impact… [A diet] that is based on plant foods is a better choice than one that is based on animal foods.”
(1) Low-Carbohydrate Diets and All-Cause and Cause-Specific Mortality: Two Cohort Studies