A new study has revealed that consuming food high in sugar and fat, such as sweets and chocolate, can actually rewire our brains to prefer unhealthy treats. The study, conducted by researchers from Harvard Medical School and published in the journal Cell Metabolism, sheds light on the neural wiring diagrams that control hunger and cravings.
The researchers uncovered a set of neurons that synapse onto and excite hunger neurons. They found that the physical connection between these neurons, known as synaptic plasticity, increases greatly with dieting and weight loss, leading to excessive hunger. This suggests that the brain undergoes rewiring in response to a high-sugar and high-fat diet, promoting further consumption of these types of foods.
To test their hypothesis, the researchers conducted an eight-week study with two groups of volunteers. One group was given a small pudding containing a lot of fat and sugar per day, while the other group received a pudding with the same number of calories but less fat.[0] The volunteers' brain activity was measured before and during the study.[1] Surprisingly, the group that consumed the high-fat and high-sugar pudding did not gain more weight than the control group, and their blood sugar and cholesterol levels remained unchanged.[2]
Lead author Sharmili Edwin Thanarajah suggests that our tendency to eat high-fat and high-sugar foods, also known as the Western diet, may be innate or develop as a result of being overweight.[2] The study's findings indicate that the dopaminergic system, which regulates motivation and reward in the brain, is activated by foods high in sugar and fat. This activates the reward circuits in the brain and leads to a mental shift towards craving junk food.
The researchers also discovered that inhibiting the neural pathways that activate hunger neurons resulted in significantly less weight gain after the diet. This finding could potentially help to alleviate the yo-yo effect of weight loss and gain.
Marc Tittgemeyer, another researcher involved in the study, explains that new connections are made in the brain when we consume high-sugar and high-fat foods, and these connections do not dissolve quickly. This suggests that the brain retains the memory of these foods, which could contribute to long-lasting cravings.
While the study did not find a direct link between consuming high-fat and high-sugar foods and weight gain or changes in metabolic markers, it does highlight the importance of food choices in maintaining a healthy body weight.[3] Frequent consumption of these types of foods can increase the risk of obesity, heart disease, and diabetes.
The American Heart Association recommends limiting the intake of foods high in saturated fats, such as butter, ice cream, and fried foods, as they can increase the risk of stroke and heart disease.[4] Similarly, excessive sugar consumption can lead to weight gain, diabetes, and heart disease.[3]
The study, conducted by researchers at Yale University and the Max Planck Institute for Metabolism Research in Germany, also found that participants who consumed high-fat and high-sugar yogurt had a decreased desire for low-fat foods and an increased brain response to high-fat and high-sugar foods.[5] This suggests that the brain adapts to overeating by decreasing the preference for low-fat items.
Overall, the study emphasizes the long-term effects of consuming a high-sugar and high-fat diet on the brain. It suggests that even individuals with no intrinsic or genetic risk for obesity can develop a risk for overeating when exposed to an unhealthy diet. The findings highlight the need to minimize consumption of processed and energy-dense foods to maintain a healthy brain and body.
0. “Sweets change our brain: Why we can't keep our hands off chocolate” Medical Xpress, 22 Mar. 2023, https://medicalxpress.com/news/2023-03-sweets-brain-chocolate.html
1. “Blame your brain for craving for unhealthy, sugary foods – Sentinelassam” The Sentinel Assam, 24 Mar. 2023, https://www.sentinelassam.com/topheadlines/blame-your-brain-for-craving-for-unhealthy-sugary-foods-642257
2. “How sweets and chocolate rewire our brains | National | douglascountysentinel.com” Douglas County Sentinel, 22 Mar. 2023, https://www.douglascountysentinel.com/news/national/how-sweets-and-chocolate-rewire-our-brains/article_0c67b648-f180-5bcf-a8c5-f42b71a41d21.html
3. “High-fat, high-sugar foods rewire brain to want more of them, study says” UPI News, 22 Mar. 2023, https://www.upi.com/Health_News/2023/03/22/germany-fat-sugar-rewrire-brain-study/9731679504284/
4. “How your favourite snacks change your brain to make you pile on weight…” The Sun, 22 Mar. 2023, https://www.thesun.co.uk/health/21801768/favourite-snacks-change-brain-pile-weight/
5. “What happens in our brains when we eat junk food?” AOL, 22 Mar. 2023, https://www.aol.com/news/sugary-fatty-snacks-change-brain-150000443.html
