How can we enjoy a tasty, fatty meal without weight gain?
Foods rich in dietary fat are known to cause weight gain if consumed excessively, and yet we still eat them because they are tasty and are in abundant supply. This article by Oleksandr Nychyk, Wiley Barton, Paul D. Cotter and Kanishka N. Nilaweera, Teagasc first appeared on RTÉ Brainstorm last week
Foods rich in dietary fat are known to cause weight gain if consumed excessively, and yet we still eat them because they are tasty and are in abundant supply. Because food preferences are hard to change, it would be fantastic if there is a way to still enjoy an occasional meal that is rich in dietary fat without the burden of excessive weight gain.
Recent research provides the first glimmer of hope of how this might be achieved based on the effects of whey proteins found naturally in milk. The researchers fed adult mice diets rich in fat for a period similar in humans to about a decade. In parallel, another group of mice were fed high fat diets supplemented with different amounts of whey proteins.
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We found that consuming high amounts of whey proteins reduced the capacity of dietary fat to cause weight gain by about 20 to 40%. There were also other improvements. Both blood glucose levels and inflammation were reduced. These health improvements occurred because whey proteins caused a change to the dietary fat inside the body.
This work is timely given the prevalence of obesity worldwide, which has tripled since 1975 and affected over 650 million adults globally in 2016. Much of this is due to intake of calorie-rich foods, especially those high in dietary fat. This work brings together a decade of research knowledge on the anti-obesity potential of dairy and it shows how specific ingredients, such as whey proteins, when extracted from milk can be used to reduce the unhealthy outcomes of high dietary fat intake.
Just how did whey proteins achieve this? Researchers used state-of-the-art DNA sequencing strategies to investigate if the microbes inhabiting the gut played a part in the mechanism of the whey protein-effect. It was found that high dietary fat intake caused the growth of microbes normally associated with excessive weight gain and related health issues such as high blood glucose levels and inflammation. This effect was changed when whey proteins were simultaneously ingested with dietary fat, causing the growth of potentially beneficial microbes. The impact of whey proteins also affected the biochemical pathways in the microbes that facilitate communication with each other and with the body.
It could be argued that these changes in the gut microbes are coincidental and not responsible for the beneficial effect of whey proteins. To address this, the researchers then took the faecal material (that contains the microbes) from donor mice fed high dietary fat and whey proteins, and transplanted them into recipient mice consuming a high fat diet. The mice that received the transplants also reduced weight gain. A 90% reduction in weight gain was achieved. This confirmed that the whey protein-effects are brought about by the microbes.
The present work is significant because we achieved a reduction in weight gain without limiting the size of the meal or its fat content, which would be the most common advice given to people to help manage their weight. Finding innovative dietary solutions to tackle the global obesity problem is more important now, given the present Covid pandemic and associated restrictions on movement. This work is now progressing towards enhancing the activity of whey proteins and associated microbes to an even higher level than that achieved in the above study, which we then aim to test in humans.
The research was led by researchers in Teagasc and involved teams in UCC, UCD and the University of Aberdeen. The research was funded by the Science Foundation Ireland in partnership with the Biotechnology and Biological Sciences Research Council and the VistaMilk Research Centre
Dr. Oleksandr Nychyk is a former SFI-funded post-doctoral researcher in Teagasc and is now a Scientific Analyst at Eurofins/Janssen Biologics. Dr. Wiley Barton is a post-doctoral researcher with the VistaMilk SFI Research Centre at Teagasc. Prof Paul Cotter is the Head of Food Biosciences at Teagasc and a Principal Investigator with the Irish Research Centre, APC Microbiome Ireland, VistaMilk and Food for Health Ireland. Dr. Kanishka Nilaweera is a Senior Research Scientist and Funded Investigator in the VistaMilk Research Centre at Teagasc.