Although the trial has several limitations, children in the low sugar group scored significantly lower across multiple measures of obesity, including BMI, weight, skinfold-thickness measurements, waist-to-height ratio, and fat mass.

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The most likely alternatives, butter and pig fat, were ruled out using a technique called isotope-ratio mass spectrometry, which measures the molecular weights of the chemicals in a sample.

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The studies measured the participants' body mass index (BMI), a ratio of their height and weight, but it wasn't able to take into account their body fat composition, or how much of their overall body weight was made up of fat versus muscle.

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