Why dietary whey proteins are good news for women
Research has found women respond better to whey protein than men when it comes to weight management. As part of a recent RTÉ Brainstorm article, Kanishka Nilaweera, VistaMilk Research Ireland Centre, explores whey protein's role in reducing fat.
Over the last century, the intake of high calorie foods has increased considerably and it is believed that this has caused the obesity epidemic and associated co-morbidities such as diabetes. In light of this issue, most weight-loss or weight maintenance dietary plans recommend switching to a low calorie diet. Whilst these are effective during the course of its implementation, they are difficult to sustain over a long period of time, leading to a gradual shift towards pre-dieting food habits, which we know to cause weight regain.
In our search to find a long term dietary solution, we made some amazing discoveries about the effects of dietary whey proteins on body fat. These proteins, found in milk, which can be separated during cheese manufacture, are generally consumed by athletes to improve muscle mass.
The first of these discoveries was the finding that dietary whey proteins have the capacity to transform high calorie dietary fats in the gut into forms that have less capacity to deposit and cause weight gain. The transformation was done by the microbes in the gut, which responded to whey protein intake.
We detailed this exciting discovery in an article published in RTE brainstorm in 2021 as a way to occasionally enjoy a tasty, fatty meal without weight gain. Our journey did not end here, as the work undertaken in the following two years to improve the effectiveness of whey proteins, led to the second discovery.
We discovered that there are specific interactions between whey proteins and other macronutrients in the diet (i.e., the dietary carbohydrates and fats), which allow a selective reduction in specific fat stores in the body. These are the abdomen-associated fat (also called the visceral fat, which mainly males accumulate) or the hip/thigh areas-associated fat (also called the subcutaneous fat, which females accumulate).
As a result, for the first time, we were in a position to tailor the diet to reduce fat storage based on the sex of the individual, either for health reasons (for reducing unhealthy visceral fat) or for cosmetic reasons (for reducing one or both types of fat based on the individuals' preference). We did not know at the time that there would be another remarkable (third) discovery, which is that the bioactivity in whey proteins has a sex preference. We found this by trying to understand the mechanisms by which dietary whey proteins reduce specific body fat stores.
In our most recent study, which focused on another high calorie macronutrient, namely carbohydrates, we discovered that dietary whey proteins when consumed with high quantities of carbohydrates cause less weight gain in females than males. The better weight management shown by females appear to relate to an increased gut capacity to break down carbohydrates. The effect reduced visceral (abdomen) and (to a lesser extent) hip/thigh (subcutaneous)-associated fat, whereas males required an extended period of intake to show a modest reduction in visceral fat.
To extend our work, and knowing how important the mothers’ diet is on the growth of their offspring, we wondered if female mice that continue to consume whey proteins into pregnancy and lactation stages could pass the bioactivity onto the offspring. To our amazement it did. We found that female offspring born to mothers fed whey proteins have increased gut capacity to breakdown carbohydrates. Furthermore, the female offspring gain less body weight and have reduced visceral and subcutaneous fat stores, just like the females in the parent generation.
This research lays the foundation for further research with human subjects to assess the impact of whey proteins on key critical stages of life, such as during reproduction. Nonetheless, the data highlight how the bioactivity in a healthy diet can be transmitted across generations, with long lasting effects; and conversely, how an unhealthy diet, can have long lasting (unhealthy) outcomes on the next generation. Interestingly, there is data to suggest that the babies born in early part of 21st century are heavier than those born in the early part of 20th century, which appear to coincide with the century in which the intake of high calorie foods had increased.