‘Pie hole’, colloquial for one’s mouth, is believed to have evolved in the USA in the 1980s from the British expression ‘cake hole’ (coined in the mid 20th century). Pie hole refers to a mouth, as in: Shut your pie hole or, in this case: Put less in your pie hole.

Wednesday, September 10, 2014

Diets: Low Carb, Low Fat or Something Else?

"Which diet is best?" Such a depressing question, but one that is still being studied because people are still asking. It's big business too, with so many boutique and 'brand' name diets available.

A new study set out to strip down the evidence and see what was left underneath. This meta analysis analysed 48 randomised control trials (kind of the gold standard when we talk about study design) that included over 7,200 people. The median age was 45, median BMI was 33 (obese).

They divided the diets thus:
  • Moderate macronutrient (55-60% of calories from carbohydrates, 15% from protein)
  • Low carb (<40% of calories from carbs, 30% from protein)
  • Low fat (60% of calories from carbs, 10-15% from protein)
One note is that most government guidelines recommend ~45-65% of daily calories come from carbs (the US recommends >50% of that come from whole grains).

Just like my labrador, who swears by her monotonous duck and legume diet, people swear black and blue about their diverse, and often dubious diets.

The analysis found that low fat and low carb dieters had the greatest weight loss success at 6 months, about 8kgs. However, at 12 months, 1-2kgs of this effect was lost (aka, people gained it back).

If you're thinking lower carb, think glycemic index (GI). Good quality, whole grain carbs are a better choice than refined foods that are high GI. For example, oats are high in fiber and harder to digest than white bread... Make your intestines work for a living. Low GI foods aid weight loss and improve blood glucose/insulin regulation.

The study also found that exercise and education on behavioural changes enhanced weight loss. Kind of like how taking swimming lessons and staying in the shallow end of the pool decrease your chances of drowning.

Even though only minor differences were found between brand name diets (eg: Jenny Craig vs Atkins vs Southbeach vs Weight Watches vs Ornish vs Nutrisystem), we can take solace in that any diet/modification resulted in weight loss compared with no changes at all.

Many such 'organised diet programs' are expensive, have high attrition rates, and a high probability of regaining 50% or more of lost weight in 1 to 2 years. You're better off spending your money on fresh food rather than fancy, fad diets fraught with fleeting and frustrating results. After all, in my class, 50% is an F... Just saying.

Take home:
  • Behaviour changes form habits, rather than short term change
  • Making changes you can actually stick to in the long term will improve weight loss

An article from earlier this year about how different brand diets stack up.