New Study Confirms That Carbs Make You Fat

Discussion in 'Health and Fitness' started by Baron, Nov 19, 2018.

  1. Baron

    Baron ET Founder

    The theory that a diet with many carbohydrates - and especially a diet with a lot of quickly absorbable carbohydrates - leads to overweight and obesity, is not new. A high carb diet allows fat cells to grow, but ensures that the rest of the body gets less energy. Says that theory. Nutritional scientists from the University of Harvard published a trial in BMJ that suggests that this theory is correct.

    Carbs, insulin and body fat
    The researchers wanted to test the 'carbohydrate-insulin model', which describes how a diet with a lot of carbohydrates makes humans fat.

    "According to this model, the processed carbohydrates that have flooded our lives during the low-fat era have raised insulin levels, driving fat cells to store excessive calories, with fewer calories, hunger increases and metabolism slows - a recipe for weight gain", says research leader Dadid Ludwig in a press release. [ November 14, 2018]

    The researchers experimented with a group of 120 healthy subjects aged 18-65 years. The subjects had a BMI of 25 or higher. Before the real experiment started, the subjects had lost 12 percent of their body weight by a slimming diet. In the 12 weeks that the study lasted, the subjects were given a diet that provided exactly enough kilocalories to maintain their new weight.

    The researchers divided the subjects into 3 groups. They gave one group a high carb diet; 60 percent of which consisted of carbohydrates. A second group received a moderate carb diet, with 40 percent of the energy coming from carbohydrates. Finally, a third group received a low carb diet, which consisted of only 20 energy percent of carbohydrates.

    In a laboratory, the researchers determined the energy consumption of the test subjects before, during and after the 12 weeks.

    A low carbohydrate diet reduced the concentration of triglycerides in the blood. That is about the same as the concentration of VLDL, the 'worst worst cholesterol'. At the same time, a low-carbohydrate diet increased the 'good cholesterol' HDL.


    In the low-carb group, calorie consumption increased by 200 kilocalories. In the high-carb group, calorie consumption decreased.


    "If this difference persists - and we saw no drop-off during [...] our study - the effect would translate into about a 20-pound [9.1 kilo] weight loss after three years, with no change in calorie intake", says first author Cara Ebbeling. "Our observations challenge the belief that all calories are the same to the body. Our study did not measure hunger and satiety, but other studies suggest that low-carb diets also decrease hunger, which could help with weight loss in the long term."

    Before the researchers divided the subjects into 3 diet groups, they measured the effect of a portion of glucose on their insulin levels. On the basis of this, they divided the subjects into 3 other groups: a group in which the insulin level hardly reacted to glucose, a group with a moderate response, and a group in which the insulin level rose sharply.

    The stronger the insulin level responded, the stronger was the effect of a low-carbohydrate diet on calorie consumption. Click on the figure below for a larger version.


    "Dietary composition seems to affect energy expenditure independently of body weight", the researchers write. "A low glycemic load, high fat diet might facilitate weight loss maintenance beyond the conventional focus on restricting energy intake and encouraging physical activity."

    "Additional research is warranted to examine the effects of glycemic load on body weight, with control of energy intake. If metabolic benefits of reduced glycemic load diets are confirmed, development of appropriate behavioral and environmental interventions would be necessary for optimal translation to public health."

    BMJ 2018;363:k4583.
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  2. CET


    The answer to the carbohydrate question is not simple but is instead complex (pun intended).
  3. bone

    bone ET Sponsor

    The bigger takeaway was that the low carb diet devotees tend to keep the weight off. Makes you feel like shit during a heavy workout, though.
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  4. Initially there is an adjustment period but I did find that after my body fully adapted I did have real strong energy for workouts. If you are lifting like a professional for hours that is a different story but for a 1 hour Crossfit workout I was still able to do the heavy Olympic lifts and conditioning back to my heavy max reps. Everybody is different I guess you should not feel horrible after a few weeks of regular lifting and being strict.
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  5. speedo


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  6. bone

    bone ET Sponsor

    I've done great on 20 grams of Carbs per day in terms of cutting weight and keeping it off. But my trainer started forcing me to eat a baked sweet potato and some oats ninety minutes before our workouts - I was just running out of gas otherwise.
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  7. Yeah I certainly don't advocate a super low number. I was shooting for 50 net carbs and that seem to work for me, evne with indoor/outdoor soccer which was pure running. You have to find the balance. I think the two things you mentioned probably took you closer to 50 net carbs with the fiber in there so 20 net was too low for your workout intensity.
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  8. Baron

    Baron ET Founder

    I'm currently doing 100g per day of low Glycemic Index carbs myself. Everybody is different, but that seems to be the sweet spot for me. If I go lower than that, my muscles feel really flat and I get no pump whatsoever in the gym.
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  9. eurusdzn


    Anyone notice a thirst proportional to carb intake? i feel the effects of a carb dose right away.
    Not diabetic or pre-diabetice yet.
    Need to be much more conscious of this and control intake better.
    Good thread...need to learn more regarding cabs and insulin.
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  10. Baron

    Baron ET Founder

    Sure that's natural. For every gram of carb intake, your body wants 2.7g of water to go with that. So the higher your carb intake, the greater your thirst.
    #10     Nov 20, 2018
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