Most Americans are overweight. Whether the goal is to live longer, ease joint pain, breathe easier, or feel more confident, it’s no surprise as many as 42% of us are trying to lose weight.
Even if you choose to get on a GLP-1 like Ozempic or Zepbound, doctors recommend the medication be paired with lifestyle changes.
Diet is one of the most important changes you can make for weight loss.
But where should you start? The main contenders include Mediterranean, keto, and plant-forward diets.
Researchers in a new study pitted the three against each other. While all helped people lose weight, one came out with clear benefits that went beyond shedding pounds.
Three different diets
The authors picked the three popular diets that provide vastly different nutrients.
The keto (aka Atkins) diet emphasizes healthy fats while severely restricting carbs (to about 4% of calories), encouraging the body to burn fat.
A plant-forward diet does the opposite, emphasizing carbs (70% of calories) while minimizing fat, to focus on whole plant foods and minimizing animal products.
The Mediterranean diet falls somewhere in the middle. About half the calories comes from carbs, a third from fat, and about a fifth from protein.
Participants in this new research had obesity, pre-diabetes and fatty liver disease, and were each randomly assigned to one of the three diets. All their food was delivered from the researchers.
Researchers tailored the calorie intake so all participants lost about 10% of their body weight over the course of four to five months.
All three diets were successful in helping participants lose weight, drop body fat, increase their sensitivity to insulin (over time low sensitivity leads to diabetes) and improve blood sugar control.
The winning diet
One diet produced the greatest improvements in liver and metabolic health: keto, the high fat, low carb diet.
In people with obesity, excess body fat increases the release of fatty acids into the bloodstream, which gets absorbed into the liver. This causes fatty liver disease, which can lead to inflammation, damage, and scarring. This can become cirrhosis, which can become life-threatening.
With keto, participants saw liver fat drop by an average of 67%, compared with 45% in both the Mediterranean and the plant-forward groups.
Researchers found that people on keto had the largest increase in glucagon, a hormone that promotes fat loss in the liver. They also saw the largest reduction in blood insulin, which also reduces fat in the liver, compared to the other two groups.
“The most surprising finding was that participants in the ketogenic diet group didn’t experience an increase in blood fat or cholesterol levels despite consuming the most fat,” author Max Petersen said.
Peterson says that with GLP-1s revolutionizing the weight loss landscape, this study shows how changing diets “can give you added benefits.”
The realities of the keto diet
Keto has a lot of benefits, including those shown in this paper. It can help people with epilepsy, endurance athletes and body builders drop fat, and even stabilize those with psychiatric disorders.
But it isn’t all sunshine and roses. Keto lets people drop weight fast, though there’s decent debate around what that so-called “whoosh effect” is — shedded pounds could just be water, not fat.
It’s also very difficult to maintain. Avoiding carbs is very restrictive and hard to keep up.
It can also lead to nutrient deficiencies and calorie depletion. Many get the notorious “keto flu,” where they feel irritable, tired, and foggy.
It’s possible keto could increase risk of heart disease, and even small intestine cancer.
The best way to decide on what diet changes are best for you is to talk to your doctor or a dietitian.
