What does weight loss really depend on: Diet, genes or insulin levels?

What does weight loss really depend on: Diet, genes or insulin levels?

A small, but comprehensive, study from Stanford University researchers has pitted low-fat diets against low-carb diets. "On both sides, we heard from people who had lost the most weight that we had helped them change their relationship to food, and that now they were more thoughtful about how they ate".

In a 600-person, year-long study, the two eating styles helped dieters drop nearly exactly the same number of pounds - and there didn't seem to be much rhyme or reason as to who succeeded on which plan, explains study author Christopher Gardner, director of nutrition studies at the Stanford Prevention Research Center. It all depends on the person - although they haven't yet been able to determine the all important characteristics that determine which camp you fall into.

Lead study author Christopher Gardner, the director of nutrition studies at the Stanford Prevention Research Center, noted that the point of the study wasn't to compare a low-fat diet to a low-carb one to see which was best for weight loss, as many previous studies have done. ‘It's because we're all very different and we're just starting to understand the reasons'.

The factors considered in the study, such as the insulin test used (INS-30) and the genetic variations identified, may not be the right ones to use - although they were considered the best at the time of the study.

At the start of the year, "participants got part of their genome sequenced, allowing scientists to look for specific gene patterns associated with producing proteins that modify carbohydrate or fat metabolism" but "neither genotype pattern nor baseline insulin secretion was associated with the dietary effects on weight loss", per a report on the study by Citizen. About half were men and half were women. At the end of the 12 months, those on a low-fat diet reported a daily average fat intake of 57 grams; those on low-carb ingested about 132 grams of carbohydrates per day.

Each group was instructed to maintain their diet for one year.

During the first 8 weeks, participants were told to limit their daily carbohydrate or fat intake to just 20g, the equivalent of a slice and a half of bread. Some people gained weight, and some lost as much as 50 to 60 pounds.

Gardner said he was pleased with the above statistics, given the average fat consumption for the participants before the study was around 87 grams per day, and average carbohydrate intake was about 247 grams. He's also keen for people to eat more "whole foods" too, whether that's a wheat berry salad or grass-fed beef. For example, a fizzy drink may be low-fat, but it's certainly not healthy. They simply stopped eating in front of the TV or in their cars. He said some people are more satiated on whole grains and some people are more satiated with healthy fats.

"Unfortunately, it still remains unclear which diet is the best for weight loss, and who the true demons really are ... carbs or fat", she says.

The study published in the JAMA medical journal ‘closes the door on some questions but opens the door to others' added the professor.

Dr Gardener's study also found that a person's genetics or insulin metabolism is not necessarily a discriminating factor when it comes to a diet's effectiveness, despite the advent and popularity of DNA diets in the weight loss industry now.

"I think one place we go wrong is telling people to figure out how many calories they eat and then telling them to cut back on 500 calories, which makes them miserable", he said.

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