Author: Michelle Harvie - November 23, 2018

Prevent Breast Cancer’s researcher Michelle Harvie takes a deeper look at the recent research hitting the headlines about low carb diets and their long term effect on health.



‘Low carb diets could shorten life’, the headlines screamed at the weekend. The research behind this statement, published in Lancet Public Health, was based around a study that followed 15,428 middle-aged adults in the USA who were all aged between 45 and 64 years old. They filled out questionnaires on their food and drink consumption, along with their portion sizes. With this information, scientists were able to estimate the calories that they were taking from carbohydrates, fats and protein. Their health was then followed over the course of 25 years to see what kind of impact their diet may have on their life expectancy.


The results were:

  • People eating a high-carb diet, with 70% of their calories coming from carbohydrates, lived for an average of 81 years
  • People eating a low-carb diet, with 40% of their calories coming from carbohydrates, lived for an average of 79 years
  • People eating a moderate amount of carbs, with around 50% of their calories coming from carbohydrates, lived for an average of 83 years.


However, just looking at their carbohydrate intake does not tell the full story, as there are many different types of low-carb diets. The researchers looked at people who followed an Atkins-style low carb diet, consuming higher amounts of animal protein and fats, including red meat and chicken, but who ate little in the way of fruit, vegetables and wholegrains. It also followed people who replaced carbohydrates with vegetable proteins and fats, such as nuts and seeds, while eating plenty of vegetables, fruit and wholegrain bread.


Predictably, the high-meat, low fruit and veg and low-carb diet was found to be very unhealthy. This group increased their of risk of dying during the 25-year follow up by 20% compared to the moderate carbohydrate eaters. The healthiest group was those who were on a low-carb diet but ate plenty of nuts, vegetables and wholegrains – they were 15% less likely to die during the study.


Mediterranean diet healthy lifestyles


The advice that can be taken from these results is that the healthiest diet is one that includes plenty of vegetables, fruit, wholegrains, vegetable proteins, healthy fats from nuts and seeds, a lower intake of red meat and a moderate amount of carbohydrates.


Our 2-Day Diet fits with these recent findings. The 2-Day Diet has two heathy low-carbohydrate days per week, which include plenty of fish, vegetable protein and healthy fats, such as olive oil and avocados, and five days of a healthy Mediterranean diet, which includes wholegrain carbohydrates, fruit, vegetables, healthy fats, dairy products, fish, lean meat, chicken and vegetable protein. The diet is an effective way to lose weight and keep it off, but could also cut the risk of breast cancer.


For more information about our diet and lifestyle research projects, take a look at our research projects.