London: Dr. Wafa Jassim Al-Rajab
Dietary guidelines have changed over the years, as research has become more accurate in determining what people should eat to achieve better results in health and optimal weight. And the strongest evidence yet, shows that calories matter. But focusing on food quality is an equally important part of preventing weight gain and promoting weight loss.
Rather than choosing foods based on caloric value only, high-quality foods include unrefined and lightly processed foods, such as vegetables, fruits, whole grains, healthy fats and healthy protein sources, which are the foods recommended on the Healthy Eating Board.
Researchers in the Department of Nutrition at the College of Public Health at Harvard University in the US, in a study conducted on more than 120,000 healthy women and men over a period of 20 years, concluded that the change in weight towards an increase was strongly associated with eating potatoes and sweetened drinks. High in sugar, and processed and unprocessed red meat, meaning rich in starch, refined grains, fats and sugars. The foods that were shown to be linked to weight loss were vegetables, whole grains, fruits, nuts, and yogurt.
Mixed nutritional responses
In a recent study published on June 11, 2020, in the journal Nature Medicine, a group of researchers headed by Tim Spector, head of the department of genetic epidemiology at King’s College London, was fed a meal for 1,102 healthy people. Identical for two weeks, measuring their metabolic responses. The results showed large differences, ranging up to ten times in their variability, which means that eating a healthy diet for one person can be unhealthy for another person.
Among the volunteers were several pairs of identical twins, who showed very different responses to the same meal.
“Everyone reacts differently to similar foods,” Spector said. He had expected to find a powerful genetic component for metabolic responses. But he saw very little.
The volunteers’ blood glucose, insulin and triglyceride levels were measured. High levels of all three of these compounds after eating are considered a risk factor for obesity, while people who show high glucose and jumps in triglyceride levels after eating are more likely to develop cardiovascular disease and diabetes.
The researchers added that genetic factors do not play a major role. In fact, other factors such as gut microbes, sleep and exercise are more important. The timing of meals is also important. Some people eat better in the morning, while other people do not see any difference in their ability to eat at any time of the day.
Spector and his team also developed an AI tool to predict individuals’ responses to food, based on their genes, gut microbes, exercise and sleep patterns, and metabolic responses to food. A UK-based company called Zoe has turned this into a consumer testing tool, and a smartphone app that will be launched in the US next month and in the UK later this year.