So that study... I'm confused

Here's a good article detailing the study.

http://www.medpagetoday.com/Cardiology/Prevention/47447

"Throughout the study, physical activity and caloric intake were similar in the two groups -- the 12-month average caloric content of the low-carb and low-fat diets was 1,448 and 1,527 calories, respectively -- and approximately 80% of participants in both groups completed the yearlong trial."

"At 12 months, individuals on a low-carbohydrate diet had lost 5.3 kg (11.7 lb), while those on a low-fat diet with similar caloric value had lost 1.8 kg (3.9 lb), for a mean difference of -3.5 kg, or 7.7 lb (95% CI minus 5.6-minus 1.4, P=0.002), according to Lydia Bazzano, MD, PhD, of Tulane University in New Orleans, and colleagues."

The net

Low carb - average 1448 cals
Low Fat - average 1527 cals

Loss Low Carb - 11.7 pounds
Loss Fat - 3.9 pounds

Thoughts?

Replies

  • kgeyser
    kgeyser Posts: 22,505 Member
    The low carb group also went from eating 240g of carbs each day to less than 40g (regardless of calorie intake), which represents a drastic shift in the way they ate - much more restrictive in the food choices they could realistically make and stay under that 40g. The low fat group went from about 35% fat to no more than 30% fat, which is a much smaller dietary shift, and did not really force them into eating differently. Couple that with the calorie deficit difference, and the study findings don't actually prove what people are claiming in terms of low carb vs low fat.
  • Kalikel
    Kalikel Posts: 9,603 Member
    My first thought is that you left a lot out. But I don't really want to read it, anyway. :)

    My second thought is, "What is confusing him?"
  • j4nash
    j4nash Posts: 1,719 Member
    My first thought is that you left a lot out. But I don't really want to read it, anyway. :)

    My second thought is, "What is confusing him?"

    The average caloric intake for both groups is very close, but the average weight loss for both groups is significant. I understand the notion that the low-fat had more options and could eat more, but how does that explain the caloric averages?
  • Kalikel
    Kalikel Posts: 9,603 Member
    My first thought is that you left a lot out. But I don't really want to read it, anyway. :)

    My second thought is, "What is confusing him?"

    The average caloric intake for both groups is very close, but the average weight loss for both groups is significant. I understand the notion that the low-fat had more options and could eat more, but how does that explain the caloric averages?
    It doesn't. A lot was left out. :)
  • j4nash
    j4nash Posts: 1,719 Member
    The low carb group also went from eating 240g of carbs each day to less than 40g (regardless of calorie intake), which represents a drastic shift in the way they ate - much more restrictive in the food choices they could realistically make and stay under that 40g. The low fat group went from about 35% fat to no more than 30% fat, which is a much smaller dietary shift, and did not really force them into eating differently. Couple that with the calorie deficit difference, and the study findings don't actually prove what people are claiming in terms of low carb vs low fat.

    The deficit was minor, at least on a daily basis, 79 cals. Is the weight loss difference over the 12 months simply due to 79 excess calories compounded over 12 months?
  • kgeyser
    kgeyser Posts: 22,505 Member
    My first thought is that you left a lot out. But I don't really want to read it, anyway. :)

    My second thought is, "What is confusing him?"

    The average caloric intake for both groups is very close, but the average weight loss for both groups is significant. I understand the notion that the low-fat had more options and could eat more, but how does that explain the caloric averages?

    Well, just using the rough numbers, that's an 80 calorie per day difference and 560 calories per week - that adds up. Over a year, that's about an 8 lb difference - which is consistent with the loss reported (11 lb low carb, 3 lb low fat).
  • eryquem
    eryquem Posts: 66 Member
    Low carb ate 79 calories per day less than low fat.

    Study lasted 1 year, so the total difference in calories consumed for the year is 28835

    28835 / 3500 = 8.23 lbs.

    Actual difference between the two groups was 7.8 lbs

    So the math actually comes in very close, and in fact favors the low fat group by a very small margin.
  • Kalikel
    Kalikel Posts: 9,603 Member
    The low carb group also went from eating 240g of carbs each day to less than 40g (regardless of calorie intake), which represents a drastic shift in the way they ate - much more restrictive in the food choices they could realistically make and stay under that 40g. The low fat group went from about 35% fat to no more than 30% fat, which is a much smaller dietary shift, and did not really force them into eating differently. Couple that with the calorie deficit difference, and the study findings don't actually prove what people are claiming in terms of low carb vs low fat.

    The deficit was minor, at least on a daily basis, 79 cals. Is the weight loss difference over the 12 months simply due to 79 excess calories compounded over 12 months?
    There is no way to know. I wouldn't worry about it. :)
  • williams969
    williams969 Posts: 2,528 Member
    The calorie difference alone accounts for the difference in weight loss between the groups (assuming all other things equal). 79 calorie/day higher in the "low fat" group => 28,835 calories more consumed than the low carb group => 28,835/3,500 ~=8.23 lbs.

    Bam! There's the difference. Nothing confusing at all.:flowerforyou: :drinker:

    ETA: Obvs eryquem types much faster than me :wink: Yeah, what they said, lol. No low-carb magic stuffs happened in that 12 months. Sorry.
  • sodakat
    sodakat Posts: 1,126 Member
    I don't see how the people in either group could be eating approximately 1400-1500 calories a day for a YEAR and only lose between 3 and 11 pounds. Something doesn't add up.
  • RHachicho
    RHachicho Posts: 1,115 Member
    Low carb ate 79 calories per day less than low fat.

    Study lasted 1 year, so the total difference in calories consumed for the year is 28835

    28835 / 3500 = 8.23 lbs.

    Actual difference between the two groups was 7.8 lbs

    So the math actually comes in very close, and in fact favors the low fat group by a very small margin.

    HAH! lol yeah it's easy to miss stuff like that. Just goes to show it's not about what you eat it's about how much.
  • fatcity66
    fatcity66 Posts: 1,544 Member
    Here's a good article detailing the study.

    http://www.medpagetoday.com/Cardiology/Prevention/47447

    "Throughout the study, physical activity and caloric intake were similar in the two groups -- the 12-month average caloric content of the low-carb and low-fat diets was 1,448 and 1,527 calories, respectively -- and approximately 80% of participants in both groups completed the yearlong trial."

    "At 12 months, individuals on a low-carbohydrate diet had lost 5.3 kg (11.7 lb), while those on a low-fat diet with similar caloric value had lost 1.8 kg (3.9 lb), for a mean difference of -3.5 kg, or 7.7 lb (95% CI minus 5.6-minus 1.4, P=0.002), according to Lydia Bazzano, MD, PhD, of Tulane University in New Orleans, and colleagues."

    The net

    Low carb - average 1448 cals
    Low Fat - average 1527 cals

    Loss Low Carb - 11.7 pounds
    Loss Fat - 3.9 pounds

    Thoughts?

    It shows you what a difference 80 calories a day can make over time!
  • bwogilvie
    bwogilvie Posts: 2,130 Member
    Dr. Yoni Freedhoff had a good post on his blog today about the study. The takeaway: most of the difference in weight loss was in the first three months, and both groups deviated substantially from the prescribed diet.

    http://www.weightymatters.ca/2014/09/what-i-learned-by-actually-reading-that.html