Science and Low Carb / Paleo

This page summarizes some of the science behind low carb / paleo diets.

Bottom line

The latest review of all major trials of low carb diets show improved weight AND improvement of all major risk factors for heart disease:

Saturated fat

Despite half a century of research there is still no evidence that natural saturated fat (like butter, eggs etc.) is anything but completely safe to eat.

Have a look at these recent reviews of all the evidence:

Insufficient evidence of association is present for intake of … saturated or polyunsaturated fatty acids; total fat … meat, eggs and milk.

There were no clear effects of dietary fat changes on total mortality or cardiovascular mortality…

no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.

But wait, what about butter and other high fat dairy specifically? Well, actually people consuming it are if anything thinner and healthier than others:

The observational evidence does not support the hypothesis that dairy fat or high-fat dairy foods contribute to obesity or cardiometabolic risk…

This means that the scientific foundation of the low fat dietary advice has fallen. The reasons for it today are mainly economical (low fat high sugar products are very lucrative and finances a lot of lobbying), combined with old-fashioned prestige and inertia.

The low fat dietary advice has become a house of cards with nothing to support it. It is just a question of time before it’s apparent to everybody.

Weight loss

Some people still claim that weight loss studies do not show any advantage for low carb diets. Unbelievably enough, that is what many so called experts still believe.

It’s either ignorance or science denial.

There are at least 18 modern scientific studies of the highest quality (RCT) that show significantly better weight loss with low carb diets:

RCTs showing significantly more weight loss with low carb diets

  1. Shai I, et al. Weight loss with a low-carbohydrate, mediterranean, or low-fat diet. N Engl J Med 2008;359(3);229–41.
  2. Gardner CD, et al. Comparison of the Atkins, Zone, Ornish, and learn Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women. The a to z Weight Loss Study: A Randomized Trial. JAMA. 2007;297:969–977.
  3. Brehm BJ, et al. A Randomized Trial Comparing a Very Low Carbohydrate Diet and a Calorie-Restricted Low Fat Diet on Body Weight and Cardiovascular Risk Factors in Healthy Women. J Clin Endocrinol Metab 2003;88:1617–1623.
  4. Samaha FF, et al. A Low-Carbohydrate as Compared with a Low-Fat Diet in Severe Obesity. N Engl J Med 2003;348:2074–81.
  5. Sondike SB, et al. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr. 2003 Mar;142(3):253–8.
  6. Aude YW, et al. The National Cholesterol Education Program Diet vs a Diet Lower in Carbohydrates and Higher in Protein and Monounsaturated Fat. A Randomized Trial. Arch Intern Med. 2004;164:2141–2146.
  7. Volek JS, et al. Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Nutrition & Metabolism 2004, 1:13.
  8. Yancy WS Jr, et al. A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia. A Randomized, Controlled Trial. Ann Intern Med. 2004;140:769–777.
  9. Nichols-Richardsson SM, et al. Perceived Hunger Is Lower and Weight Loss Is Greater in Overweight Premenopausal Women Consuming a Low-Carbohydrate/High- Protein vs High-Carbohydrate/Low-Fat Diet. J Am Diet Assoc. 2005;105:1433–1437.
  10. Krebs NF, et al. Efficacy and Safety of a High Protein, Low Carbohydrate Diet for Weight Loss in Severely Obese Adolescents. J Pediatr 2010;157:252-8.
  11. Summer SS, et al. Adiponectin Changes in Relation to the Macronutrient Composition of a Weight-Loss DietObesity (Silver Spring). 2011 Mar 31. [Epub ahead of print]
  12. Halyburton AK, et al. Low- and high-carbohydrate weight-loss diets have similar effects on mood but not cognitive performance. Am J Clin Nutr 2007;86:580–7.
  13. Dyson PA, et al. A low-carbohydrate diet is more effective in reducing body weight than healthy eating in both diabetic and non-diabetic subjects. Diabet Med. 2007 Dec;24(12):1430-5.
  14. Keogh JB, et al. Effects of weight loss from a very-low-carbohydrate diet on endothelial function and markers of cardiovascular disease risk in subjects with abdominal obesity. Am J Clin Nutr 2008;87:567–76.
  15. Volek JS, et al. Carbohydrate Restriction has a More Favorable Impact on the Metabolic Syndrome than a Low Fat Diet. Lipids 2009;44:297–309.
  16. Partsalaki I, et al. Metabolic impact of a ketogenic diet compared to a hypocaloric diet in obese children and adolescents. J Pediatr Endocrinol Metab. 2012;25(7-8):697-704.
  17. Daly ME, et al. Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes–a randomized controlled trial. Diabet Med. 2006 Jan;23(1):15–20.
  18. Westman EC, et al. The effect of a low-carbohydrate, ketogenic diet versus a low- glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr. Metab (Lond.)2008 Dec 19;5:36.

The first 16 studies in the list are weight loss trials, the last two are studies on type 2-diabetics (usually overweight) showing the same effect. Many of the studies are of six months or one year duration, one of them (Shai et al) is two years long.

All of these studies show significantly more weight loss for the group that were advised to eat a low carb diet (Atkins, in most cases).

As far as I know the opposite has never been shown: low carb has never lost a weight loss trial significantly. This means that low carb is winning versus the failed low fat/low calorie advice by 18-0!

Feel free to let me know of any exceptions (or more examples) in the comments.

Update an expert

It’s not OK for “experts” to keep denying all these modern trials. It’s time for them to take the science seriously.

Feel free to copy or link to this list, if you encounter an expert who needs an update.

The science of low carb

Here is the opinion of a true expert on low carb diets, dr Eric C. Westman, MD and president elect of the ASBP (weight loss doctors):

More

LCHF for beginners

Science for smart people

1 2 3 4

151 Comments

  1. Dietary Carbohydrate Modifies the Inverse Association Between Saturated Fat Intake and Cholesterol on Very Low-Density Lipoproteins
    Free full text at link
    We aimed to investigate the relationship between dietary saturated fat on fasting triglyceride (TG) and cholesterol levels, and any mediation of this relationship by dietary carbohydrate intake.
    Men and women in the NHLBI Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN) study (n = 1036, mean age ± SD = 49 ± 16 y) were included.
    Mixed linear models were run with saturated fat as a predictor variable and fasting TG, very low density lipoprotein cholesterol (VLDL-C), low density cholesterol (LDL-C) and high density cholesterol (HDL-C) as separate outcome variables.
    Subsequent models were run which included dietary carbohydrate as a predictor variable, and an interaction term between saturated fat and carbohydrate.
    All models controlled for age, sex, BMI, blood pressure and dietary covariates.
    In models that included only saturated fat as a predictor, saturated fat did not show significant associations with fasting lipids.
    When carbohydrate intake and an interaction term between carbohydrates and saturated fat intake was included, carbohydrate intake did not associate with lipids, but there was an inverse relationship between saturated fat intake and VLDL-C (P = 0.01) with a significant interaction (P = 0.01) between saturated fat and carbohydrate with regard to fasting VLDL-C concentrations.
    Similar results were observed for fasting TG levels.
    We conclude that, when controlling for carbohydrate intake, higher saturated fat was associated with lower VLDL-C and TGs.
    This was not the case at higher intakes of carbohydrate.
    This has important implications for dietary advice aimed at reducing TG and VLDL-C levels.

    So when is Saturated fat harmful?
    When it is associated with higher carbohydrate intakes.
  2. Thanks for this great collection of articles outlining the importance of eating saturated fats and dismissing the false science that has fueled a huge industry of low-fat foods that has caused such harm to our health. I sure hope more people in the US learn about this and change their diets.
  3. RP
    Are there similar studies showing the adoption of a LCHF diet decreases LDL cholesterol, total cholesterol or even outcomes like coronary artery disease?
  4. Zepp
    @3
    No, not that much, thats a over simplicity explanation, and its goes in the other direction to.

    The old thougts was that fat course high cholesterol and that was the reason to heart diseses, its not.

    High colesterol is more complicated then that, but some whith syndrom X and similar condition often get better blod lipids, becuse high insulin levels provoke the liver to produce a lot of triglycerids an smll LDL.

    One thing you can say is that more fat and less carbs often result in better HDL/LDL ratio and lower VLDL.

    Its this fat/cholesterol hypotes thats totaly wrong!

  5. Dana
    I apologise in advance if I have overlooked an article but has there been any studies done where they look at the effects on weight or metabolic change in average weight people taking this type of diet?
  6. Alexandra M
  7. Zepp
    Very low-carbohydrate (ketogenic) diets are popular yet little is known regarding the effects on serum biomarkers for cardiovascular disease (CVD). This study examined the effects of a 6-wk ketogenic diet on fasting and postprandial serum biomarkers in 20 normal-weight, normolipidemic men. Twelve men switched from their habitual diet (17% protein, 47% carbohydrate and 32% fat) to a ketogenic diet (30% protein, 8% carbohydrate and 61% fat) and eight control subjects consumed their habitual diet for 6 wk. Fasting blood lipids, insulin, LDL particle size, oxidized LDL and postprandial triacylglycerol (TAG) and insulin responses to a fat-rich meal were determined before and after treatment. There were significant decreases in fasting serum TAG (−33%), postprandial lipemia after a fat-rich meal (−29%), and fasting serum insulin concentrations (−34%) after men consumed the ketogenic diet. Fasting serum total and LDL cholesterol and oxidized LDL were unaffected and HDL cholesterol tended to increase with the ketogenic diet (+11.5%; P = 0.066). In subjects with a predominance of small LDL particles pattern B, there were significant increases in mean and peak LDL particle diameter and the percentage of LDL-1 after the ketogenic diet. There were no significant changes in blood lipids in the control group. To our knowledge this is the first study to document the effects of a ketogenic diet on fasting and postprandial CVD biomarkers independent of weight loss. The results suggest that a short-term ketogenic diet does not have a deleterious effect on CVD risk profile and may improve the lipid disorders characteristic of atherogenic dyslipidemia.

    http://jn.nutrition.org/content/132/7/1879.abstract

  8. Zepp
    Twelve healthy normal-weight men switched from their habitual diet (48% carbohydrate) to a carbohydrate-restricted diet (8% carbohydrate) for 6 weeks and 8 men served as controls, consuming their normal diet. Subjects were encouraged to consume adequate dietary energy to maintain body mass during the intervention. Total and regional body composition and fasting blood samples were assessed at weeks 0, 3, and 6 of the experimental period. Fat mass was significantly (P <or=.05) decreased (-3.4 kg) and lean body mass significantly increased (+1.1 kg) at week 6. There was a significant decrease in serum insulin (-34%), and an increase in total thyroxine (T(4)) (+11%) and the free T(4) index (+13%). Approximately 70% of the variability in fat loss on the carbohydrate-restricted diet was accounted for by the decrease in serum insulin concentrations. There were no significant changes in glucagon, total or free testosterone, sex hormone binding globulin (SHBG), insulin-like growth factor-I (IGF-I), cortisol, or triiodothyronine (T(3)) uptake, nor were there significant changes in body composition or hormones in the control group. Thus, we conclude that a carbohydrate-restricted diet resulted in a significant reduction in fat mass and a concomitant increase in lean body mass in normal-weight men, which may be partially mediated by the reduction in circulating insulin concentrations.

    http://www.ncbi.nlm.nih.gov/pubmed/12077732

  9. wong edan
    I am sorry to say this, but this high fat diet doesn't work for me. I lost 2 lbs in the first week, but I got gout on my feet. It hurtssss.
    Reply: #58
  10. Zepp
    Hm.. and why do you eat a lot of meat then.. or is this the case?

    You know this is a fat diet.. and if one have problems about gout one shouldnt eat more protein then one needs.

    And about gout.. this was before thougt to be caused by eating a lot of meat.. but today its more linked to metabolic syndrome!

    "Dietary causes account for about 12% of gout,[2] and include a strong association with the consumption of alcohol, fructose-sweetened drinks, meat, and seafood.[4][8] Other triggers include physical trauma and surgery.[6] Recent studies have found dietary factors once believed to be associated are, in fact, not; including the intake of purine-rich vegetables (e.g., beans, peas, lentils, and spinach) and total protein.[9][10] The consumption of coffee, vitamin C and dairy products as well as physical fitness appear to decrease the risk.[11][12][13] This is believed to be partly due to their effect in reducing insulin resistance."

    http://en.wikipedia.org/wiki/Gout

    And if one do realy have gout.. one should reduce purin rich foods to its minimal as one in every case do get a minimum of essentiall aminoacids.

    And in the mean time use much C-vitamin and coffe to reduce your symptoms!

    Do you have any symptoms of insulin resistance??

  11. Hey Dr. Eenfeldt. Great stuff. Here is an 18th study. Just came out.

    In type 2 diabetes, randomisation to advice to follow a low-carbohydrate diet transiently improves glycaemic control compared with advice to follow a low-fat diet producing a similar weight loss.

    You can access the full article here: http://www.springerlink.com/content/b56453v536503166/fulltext.html

  12. grinchman
    This message is misleading. I think in free-living studies its fair to say that ad lib low-carb diets will result in greater weight loss than low-fat or other calorie restrictive diets. One confounder is the varying amounts of protein, which is often higher on low carb diets. If you actually count calories though, you will see the low-carb dieters are eating less, which explains the added weight loss.

    However in 70 years, there has not been a single metabolic ward study that compares isocaloric high and low carb diets (w/protein controlled) and shows a metabolic advantage of low carb diets. So the only advantage of low-carb diets for the purposes of weight loss is the appetite blunting effect.

  13. grinchman,

    So the only advantage of low-carb diets for the purposes of weight loss is the appetite blunting effect.

    If so, that is still brilliant right?

    To lose weight you should probably eat less. With low carb you will want to eat less. Smart or what?

  14. grinchman
    Yeah I'm all for that and eat a low carb diet myself. But I don't think it is typically pitched like that in the low carb community. I think when these studies are conveniently ignored (as you yourself didn't mention the ties), people start getting the impression that calories don't count, and wonder why they plateau with tons of weight left to lose. They think its the packet of Splenda in their morning coffee that might've triggered an insulin response, when in reality their carb restriction simply did not result in a caloric deficit.
  15. Zepp
    Well there are probably different effects on different persons I think.

    If one is obese.. one needs more insulin to make the fat stay in fattcells.. with lower insulin levels you get higher lipolysis in your fat cells and then you have energy in your blood and dont need to eat that much.

  16. I'd like to ask a question about cholesterol. This morning I was talking to a neighbour who said that last year she had a fairly high cholesterol reading of 6.9 (UK measurement). She's about 61 years old, slim, fit and walks every day - so not an unhealthy-looking person. (I think she may be a vegetarian or eat fish plus vegetarian.) She said, 'I do eat quite a lot of cheese, so I cut down and my cholesterol level went down to 5.5, which is OK.' So my question is, why did she have that effect if fats don't actually affect cholesterol levels? I know you don't have many details here, and we don't know the HDL level, but it does seem strange to me. I eat low-carb and probably more coconut products than dairy. I'm still finding it hard to accept that I can eat these saturated fats and be healthy (years of the low-fat mindset are hard to shift).
  17. Zepp
    Well there are peopel that is so cald hyperresponder!

    They do get higher total lipid levels on a hig fat diet.. but almoste everyone do get better or the same quota!

    http://atvb.ahajournals.org/content/3/4/349.short

  18. sophie
    @Zepp:

    You mentioned insulin resistance as a possible explanation for lack of results. Can you expand on its symptoms/signs and consequences?

    I got very tired everytime I ate grains (before I started LCHF) and it still happens to me after a big meal of 2 sausages and 2 eggs.

    What are some other reasons that may impede success?

  19. Zepp
    Did I.. well if one realy is insulin resistante, then you have a damaged glucose metabolism.

    And typical symptoms is high blood glucose levels and high levels of insulin.

    Many obese persons is in some level insulin resistant, with higer then normal insulin levels.. becuse there is a need for more insulin to get the fat to stay in the fat cells.

    Insulin inhibits lipolysis how is the process to break down triglycerides to free faty acids how then can be used as energy to your cells.

    When one eat, a lot of blood do goes to your guts and your digestal system, its take a lot of energy to digest and metabolice food.. so almoste everybody do have som energy defecits ounder the postprandial time.

  20. Deb
    I've been on a true low carb diet since October 2011. I eat all the fats and meats I like, some green veg and no fruit or fake low carb foods, etc. At the start of this diet, my total cholesterol was 398, and this was with taking statin drugs at that time. I have just had my cholesterol checked again, and I did not tell my doctor (yet) that I stopped the statin drugs back in October, nor did I tell her the kind of diet I have been on since then...my total cholesterol is now 180! My blood pressure is normal, my sugar is normal, and so on...She said, "Keep doing what you're doing! It works!"
  21. Endy
    Ok Deb....I really laughed after reading your post. I would like to read the description of your Doc's face when you tell her what you 've been doing.

    I am still learning about the LCHF way of eating and only started today. I hope to get good results.

  22. This page talks about low carb / paleo diets, but I went to http://thepaleodiet.com/faq#basics and there it says that low-carb high saturated fat diets are bad, and people should eat fruits. Isn't this contradicting the advice given here? Should I trust the papers listed here or those referenced on http://thepaleodiet.com/published-research?
  23. @ Grzegorz Adam Hankiewicz
    I think you'll find Loren Cordain's views on the dangers of Saturated fat are somewhat more nuanced than you've indicated.

    I live in Lincolnshire UK where local Lincoln Red Cattle finish well on grass so spend most if not all the year outdoors with direct access to grass. The meat from those animals is readily available from local butchers. Grassfed meat has benefits that affect the way our body is able to deal with inflammation and oxidation. I get Raw Milk/butter/cheese direct from the local dairy.

    Diet Doctor's post Saturated Fat and the European Paradox should give us cause to question if the experience of corn fed industrialized, intensively reared/housed meat/dairy production that is the reason US meat/dairy is relatively cheap is when combined with a high refined carbohydrate and high sugar/fructose intake is a different scenario altogether.

  24. Ed
    @Grzegorz Adam Hankiewicz
    The studies referenced only look at fats, they do not look at carb content. I think there is agreement that a diet high in fat and high in carbs is not healthy. If one replaces carbs with fat, risk factors for CVD improve.
  25. It would be a terrific thing if people unlearned the dangers of saturated fat, and stopped believing "the big Fat lie". Unfortunately the warnings about "heart healthy" has become "in-grained" (pardon the pun) - and until there is a concerted effort to educate our population, the obesity and diabetes problems will increase!
  26. Craig
    The link to the A to Z study is broken. It should be http://jama.jamanetwork.com/article.aspx?articleid=205916
  27. ATM
    Long-term effects of a ketogenic diet in obese patients http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/
    decreases in LDL, TGs, BG and increase in HDL on keto.
  28. I have found that the only way I seem to lose weight is to cut out bread, potatoes, white rice and sugar. Even if I keep the calories down that I eat, I still don't lose the amount of weight that I can lose by cutting out white carbs.
    Reply: #29
  29. Larvalis
    me too plus pasta or anything floury. I am addicted to bread so I have rye crackers instead.
  30. Matt
    I'm lifting weights to put on muscle mass. I'm also running more now than I have ever run. Is impossible to go LCHF, run 15-20 miles per week and still gain muscle weight?
  31. Zepp
    To gain muscles,, extra energy, protein and training!

    To loos weight.. energy limitation and resting, best is to make the limitation go by natural causes.. like LCHF!

    The Art and Science of Low Carbohydrate Performance

    http://www.amazon.com/The-Art-Science-Carbohydrate-Performance/dp/098...

  32. Hi Andreas

    Thanks so much for putting this article together, and importantly, such a good selection of references.

    I have been eating low carb for quite a while now and it has helped me to lose body fat, keep a very nice energy level ALL DAY, and also allowed me to help my clients to lose excess fat easily and without hunger.

    I see many discussions about whether insulin, leptin or all manner of other things are responsible for fat storage/mobilisation, but at the end of th day, low carb/high fat works, full stop.

    thanks for a great resource

  33. Sakari Peltola
    Hi!

    I was just thinking... If you're obese and then start to loose weight. Then wouldn't the fat from your body go to your bloodstream and make you fat again if fat was fattening??? And wouldn't your cholestrols etc. go up hence there would be so much exces fat in your blood???

  34. Zepp
    No.. not if you use it as energy for your cells.

    The fat enters your blood from your guts by mostly chylomicrons, they deliver fat to cells, adipote tissue and to the liver.. perticuly if you altso have high insulin levels.

    When it reach liver its broken down and rebuilt to VLDL, how goes out in the blood again, to deliver fat and cholesterol to your cells.. and ones again.. if the insulin level is to high.. then its going to adiopote tissuie for storing.. you geting fatter!

    But if the insulin level goes down, then your cells need fat as energy and its relesed as FFA, (Free Fatty Acids), bonded to albumin, how is the form for transporting fat for cell energy from adiopote tissuie.

    And if your cells get all energy it need, then your not that hungry anymore.. and probably eat less?

    If one do have a lot of fat in ones blood, then its often becuse of metabolic syndrome.. how is mostly caused by high glycemic load and a hereditet weaknes for that.

    "One of the more remarkable results from Jeff Volek’s laboratory in the past few years was the demonstration that when the blood of volunteers was assayed for saturated fatty acids, those who had been on a low carbohydrate diet had lower levels than those on an isocaloric low-fat diet. This, despite the fact that the low-carbohydrate diet had three times the amount of saturated fat as the low-fat diet. How is this possible? What happened to the saturated fat in the low-carbohydrate diet? Well, that’s what metabolism does. The saturated fat in the low-carbohydrate arm was oxidized while (the real impact of the study) the low-fat arm is making new saturated fatty acid."

    http://rdfeinman.wordpress.com/2012/02/

  35. >>>I was just thinking... If you're obese and then start to loose weight. Then wouldn't the fat from your body go to your bloodstream and make you fat again if fat was fattening???

    But fat is not fattening. That's why you go on a Low-Carb High Fat diet. Your body goes into a fat burning mode when you eliminate carbs. You burn the fat in your food and the fat from you fatty tissue.

    What's fattening is carbs. When you eat carbs your blood sugar rises, which causes your insulin to rise, and insulin regulates fat storage. When insulin is high free fatty acids form triglycerides in fat tissue, and are stuck there until they breakdown, and insulin keeps them from breaking down too!

    >>> And wouldn't your cholestrols etc. go up hence there would be so much exces fat in your blood???

    There are good cholesterols and bad cholesterols. (HDL is considered good, LDL small particle size is bad). On a LCHF diet the HDL levels generally go up and the LDL levels generally stays the same, but the LDL particle size improves. At the same time circulating triglycerides also drop. All of those factors improve your risks for chronic diseases.

    Also, while there may be more fat in circulation, there is less blood sugar so your body metabolizes the fat.

    And thats the goal of any weight loss diet, to burn stored fat.

    ES

  36. Sakari Peltola
    Hi!

    Yes, I know those things from the information I´ve recieved from these webpages and many others. The science behind low-carb high-fat diet seems strong enough to challenge hi-carb diets anytime.

    And I´m just trying to move into nice ketogenic state with my metabolism myself.

    I was just trying to come up with even more ways for people to see the evident fact that fat is not the problem, but the carbs are. (but especially that fat isn´t!!)

    Most of the people are so deep in this paradigm that it´s just like a religion with emotional response when you try to say that "It´s not the fat it´s the carbs". (In Finland at least) No matter how delicate you try to be.

    And therefore I came up with this idea that if fat was fattening then loosing weight trough burning fat from your fatcells would increase your health problems. That was intentional fiction with what I was trying to make a point. I think I wasn´t clear enough?

    Is there a huge difference in the way our bodies digest fat that comes from our fatcells and the fat that we eat???

    Am I making any sence at all?

  37. Zepp
    Its diferent metabolic paths, in some parts.

    The meal fat comes by chylomicrons and/or VLDL to your cells.

    The fat from fat cells comes by FFA, its relesed by lipolysis in absent or low insulin levels.

    And if one do eat to little carbs then ones body emediate need for fuel, then the lipolysis get higher.. and when your levels of FFA is high your cells cant burn them all.. so a lot goes to the liver.. how covert a lot of them to keton budies.

    The liver have no enzyms to burn keton budies, so it goes ut in your blood.. and there its goes to any other cell thet want to use it.

    In the end the fat is oxidised to water an carbon dioxid!

    And a notation.. chylomicrons altso activate fat storage, by ASP!

  38. Does anyone have any comments to make about this latest study?:

    Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies

    http://www.bmj.com/content/345/bmj.e7666

    Quotes:

    'Conclusions There is high quality, consistent evidence that reduction of total fat intake has been achieved in large numbers of both healthy and at risk trial participants over many years. Lower total fat intake leads to small but statistically significant and clinically meaningful, sustained reductions in body weight in adults in studies with baseline fat intakes of 28-43% of energy intake and durations from six months to over eight years. Evidence supports a similar effect in children and young people.'

    'Implications for public health policy and research

    Although it may be difficult for populations to reduce total fat intake, attempts should be made to do so, to help control weight, where mean total fat intake is 30% or more of energy. For populations where the mean total fat intake is below 30% of energy then interventions to restrict rises in total fat intake to over 30% of energy may help to avoid obesity. High quality trials are needed to examine the effect on body weight of reducing fat intake in developing or transitional countries with total fat intakes greater than 30% of energy, and of preventing total fat intake rising above 30% of energy in countries with total fat intakes of 25-30% of energy. High quality trials are also needed in children.'

  39. @Jan

    They included only low-fat vs control groups studies. Since they didn't include studies that included low-carb as one of the diets tested, no conclusion can be drawn concerning a comparison between low-fat and low-carb. However, since there are studies that compare low-carb and low-fat (the 18 studies above), and since those studies show low-carb to be superior to low-fat for weight loss, we can safely assume that whatever results the low-fat meta-analysis study found would have been bested by low-carb. This is the logic of similarity. If two are equal to a third, then all are equal to each other. Or, if A is greater than B, and if B is greater than C, then A is greater than C, and A is still greater than B.

  40. Thank you Martin.
    Reply: #41
  41. Zepp
    There is a lot of evidence that a Cambrigde diet does work altso!

    But nobody cant live like that a whole life!

    Calorie restriktion does work, the thing is that free living peopel dont seems to be able to stand a such regim a long time!

    Low carb high fat diets seems to be a more sustainable diet, and it lower ones apetite if one have a lot of fats stored.

  42. melissA
    question about excercise. i was curious, if lets say i found my hunger under control and wanted to work out= weight lift... will i burn more , plus i don't want to be bodybuilder but just lean toned, will it help?
  43. @ melissA "question about excercise....will it help?"
    Yes Exercise is good for the heart and health generally providing you don't take it to excess.
    The debate about exercise as a primary control factor for weight loss usually fails to take into account the fact that metabolism rate changes as a result of exercise.
    There is an interesting article here Dieting vs. Exercise for Weight Loss explaining what actually happens in hunter gatherer societies.
  44. PhilT
    Exercise that builds muscle is good, as muscle burns more calories than fat per kg so someone with lots of lean muscle will have a higher metabolic rate than a tub of lard.

    The energy consumed during the exercise is normally not massive - a few hundred calories more than sitting around - so don't bet too much on cardio exercise for weight loss.

  45. @PhilT

    That makes sense, until you realize that a heavier guy has to carry around a heavier weight, therefore must spend more energy. Think about it for a second.

    To lift a weight, it requires energy. To lift a heavier weight, it requires more energy.

    I'm sure you understand the First Law of Thermodynamics that says energy can't be created. If a heavy guy has to carry around more weight than a lighter guy just because he's heavier, where does the heavy guy get the extra energy required to carry around this extra weight? He's gonna eat more, of course.

    But what if the heavy guy eats exactly as much as the lighter guy? He's gonna spend less, or he will lose mass. We can't predict what kind of mass he'll lose, but if he doesn't spend less, he'll lose mass for sure. Now what if the heavy guy can't lose mass because of some metabolic problem? If he can't lose mass, he'll spend less. There is no other choice. Now what if this metabolic problem is not some genetic defect or something? Maybe it's from the environment. Maybe there's something outside that affects his metabolism, and this is why he can't lose mass, even if he eats less than he should, even less than the lighter guy.

    Look at the list of 18 studies above. Those are experiments that try to find out just what's that thing that prevents people from losing mass, even when they eat less. Those studies are dietary studies, so you might think well they're just looking at calories. No, they're looking at macronutrients, and the effect of those macronutrients on metabolism. But more specifically, they're trying to find out what happens to fat tissue - inside fat cells - when you change the ratio of fat and carbohydrate intake. This has nothing to do with muscle cells spending more or less energy. It's got to do with how quickly or slowly fat cells take in and release fat, depending on how much carbs and fat we eat.

    Here's a funny thing. In those studies, they found that when you cut carbohydrate intake by a lot, you eat less without even thinking about it. Now maybe they lose weight because they eat less. But maybe they eat less because they're just not as hungry anymore. Remember the heavy guy. He's heavy so he spends more energy, so obviously when he eats, he eats more than the lighter guy. But here, people are losing weight, are less hungry, so of course they eat less. But like the heavy guy, they don't lose weight because they eat less, instead they eat less because they're getting lighter. Another funny thing is that people who cut carbs say they have more energy. It makes no sense if you look at calories, since they eat less. But it makes perfect sense when you look at what happens to fat tissue, inside fat cells. They have more energy because now their fat cells can release fat more quickly. They've removed the metabolic problem.

  46. I am curious if exercise can help reverse insulin resistance? If insulin works mainly in the muscles it makes sense that exercising the muscles will make positive changes in their functions.
    Reply: #173
  47. @Melissa

    Take a look at this video. It's a woman who performs a lift called the power clean.

    http://www.youtube.com/watch?v=6TlbDQUWs0s

    I don't know about you, but in my opinion, she looks real fine. If you're scared that you'll build ugly large muscles by lifting heavy weights, well that video should prove you won't. You'll get stronger and gain endurance, but you won't grow muscles that much.

    The thing about muscle mass is that the primary determinant of muscle mass is testosterone. The more testosterone, the more muscle mass. That's why bodybuilders inject testosterone. They want big bigger biggest muscles. Lifting heavy weights is not enough to grow huge muscles. As a woman, you have much less testosterone than a man. So even if you lift heavy weights for years, you won't grow that much bigger muscles.

    An advantage of lifting heavy weights vs jogging is that you can get it done in about 15 minutes, 2-3 times per week. And you're done.

  48. @eddacker

    Insulin works in all tissues, not just the muscles. Nor does insulin work "mainly" in the muscles. For example, in the liver, it regulates glycolysis, lipolysis, ketogenesis, and glycogenolysis, to name a few. In fat tissue, it regulates fatty acid esterification, and triglyceride desterification. In muscle tissue, it regulates protein synthesis, and glucose/fatty acids/ketones metabolism. In the brain, it regulates hunger, and various other functions.

    In fat cells, insulin also regulates what's called adipocyte differentiation and proliferation. This is the mechanism of changing pre-adipocyte to mature adipocyte, and increasing the number of adipocytes.

    In my opinion, exercise can affect insulin resistance. But I'm not sure this is always true in all circumstances. Imagine you don't eat any carbs. If exercise reduces insulin resistance, then muscle cells can now take in more glucose, but since you don't eat any glucose, you're going to run out pretty quickly. You might imagine that you'd "hit the wall" like that. But you'd be wrong. A few months ago, there's one ultra-marathoner who decided to start a ketogenic diet. That's a diet that contains almost no carbs. He won by a wide margin. Broke his previous records, etc. He obviously didn't hit the wall. He obviously didn't spend much glucose. So, maybe here exercise doesn't really do anything for insulin resistance in muscle cells.

    But that's not a problem. Muscle cells can use ketones instead. When you cut carbs, your liver starts producing much more ketones than otherwise. This happens mainly because insulin level drops. So we can see why this ultra-marathoner won and broke records. And he didn't hit the wall. So maybe exercise doesn't do much for insulin resistance in muscle cells, but with lots of ketones, it doesn't matter much.

    Reply: #52
  49. Zepp
    eddacker.. exercise do empty your muscle cells of energy.. one use it in the exercise.. then its more space to store new energy.. and that means that you dont need that much of insulin to make it go from your blood in to your cells!

    And ofcourse.. with more muscles, more space to store glucose!

    Its about allocation of GLUT4, how is glucose transportation chanels in your cells how reacts to insulin signaling.. and/or internal energy demands.

    But.. but.. its more complicated then that.. some do have damaged there signaling pattern.. how should react on insulin.. and to that.. high levels of FFA in the form of NEFA, seems to block the reaction to allocate GLUT4 to the surface of the cells!

    And that state often is found in Metabolic syndrome.. one have high blood sugar and high blood lipids!

    And to that.. one never have more GLUT4 then one need.. its about time/energy regulation!

    Exercise give you more muscles, more space to store glucose, more GLUT4, and deplet some of the energy in your cells!

    Reply: #53
  50. melissA
    wow ty i feared big muscles awesome ty
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