Today I watched a documentary called “Why are we getting so fat?” featuring Dr. Giles Yeo, a Cambridge University geneticist. What intrigued me so much about the film was the concept that some people are genetically predisposed to gaining weight because of an identified variant in their genetic makeup, called FTO, for “fat mass & obesity- related transcript”.
There are over 100 genes involved in obesity, and one half of the population has FTO1 risk-variant, which can lead to overweight. However, the real culprit is the FTO2 variant, which is found with people who are or can become morbidly obese.
FTO makes the brain less sensitive to cues that manage our satiety and weight; a) you think you are less fat than you are and b) you think you eat less than you do. The reward pathways are skewed, and this is dangerous for some in an obesogenic environment, or ‘the sum of influences that the surroundings, opportunities, or conditions of life have on promoting obesity in individuals or populations' (https://www.ncbi.nlm.nih.gov/pubmed/17152319). Simply put, we are in a place in our evolution where there is “so much to eat, and so little to do”, according to Dr. Yeo.
There is good news. In a simple test, when a group of people who were identified as having the FTO2 variant knew it, they did one of two things the next time they ate. They either chose not to eat anything or they made a low-calorie food choice. This knowledge helped people make some better choices and be mindful of what they were consuming. Researchers conclude this is helpful information for weight management.
The only thing that is helping morbidly obese people right now is bariatric surgery because it not only causes a reduction in weight because the procedure reduces stomach size, but some doctors believe it also changes the hormones associated with weight (cortisol and ghrelin). Trials at the Hammersmith Hospital in London are testing injections to control the hunger hormones, instead of surgery.
In the US, at the Brigham and Women’s Hospital a trial is testing the idea of inserting feces from lean donors to obese patients to affect weight loss. Doctors believe the key is to isolate the individual bacteria out of the millions in our gut microbiome that is linked to weight loss. Researchers have identified the Christensenellaceae microbe as a factor in protecting against weight gain, with the leanest among us having the most of it.
All these new insights and clinical trials give hope for people who are extremely overweight and consider more drastic measures to improve their health and quality of life. It is always a question of nature vs nurture, in understanding why some people get heavy while others stay slim.
The conclusion is that genes, environment and diet are all important. More diversity and high fiber in a diet has been shown to be able to manipulate the bugs in our gut. The best diet is one with a wide variety of food, full-fat yogurt and even dark chocolate.
You may remember a few issues back, I lauded the Mediterranean diet as the one that is the best overall for weight maintenance and I was so glad to hear these scientists agree.
If you would like to find out more about the Mediterranean diet, you may download some free recipes here to try. If you would like to participate in a free Mediterranean diet challenge with me sign up here. The challenge will start on Sunday, February 24. I hope you can make it!
Have a healthy week!