Many people today try extreme diets to lose weight or control their blood sugar. Some avoid carbs, while others cut back on fats.
These diets might help in the short term, but a new study from Japan shows they may not be the best for living a long life.
The study was done by researchers from Nagoya University Graduate School of Medicine and led by Dr. Takashi Tamura. It was published in The Journal of Nutrition and followed over 81,000 Japanese adults for nine years.
The researchers wanted to find out how carbs and fats in the diet affect a person’s risk of dying. They looked at both men and women and studied not just how much of each nutrient people ate, but also the types of carbs and fats—whether they were healthy or not.
The results were surprising. Men who got less than 40% of their daily energy from carbs had a higher chance of dying, especially from cancer. This was true whether the carbs were refined or unprocessed. Women, on the other hand, who ate a lot of carbs—more than 65% of their daily calories—also had a higher risk of dying.
When it came to fats, men who ate more than 35% of their daily calories from fats had a higher risk of dying from cancer.
They also found that men who ate less unsaturated fats—the healthy kind—had a higher risk of dying. But for women, the story was different. Women who ate more fat, including saturated fat (usually seen as unhealthy), actually had a lower risk of dying.
The researchers believe this might mean that women benefit differently from fats than men do. It could also mean that other nutrients found in fatty foods, not just the fat itself, play a role.
This study is important because low-carb and low-fat diets are very popular. Many people think they are a good way to improve health. But this research shows that going to extremes might not be the best plan if you want to live a long life. Eating too few carbs or too little fat could be harmful in the long run.
What can we learn from this? Balance is key. Men should avoid very low-carb diets, and women should be careful not to eat too many carbs. Women may benefit from a diet that includes more fat. The best diet is one that includes a variety of healthy foods without cutting out major food groups.
In the end, the study suggests we should stop focusing only on how many carbs or fats we eat and instead look at the bigger picture—how to eat a well-balanced diet that supports long-term health and lowers the risk of serious illness or early death.
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The study is published in The Journal of Nutrition.
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