Another study showing low-carb better than low-fat

[MeSci]

http://www.ncbi.nlm.nih.gov/pubmed/25178568

Effects of low-carbohydrate and low-fat diets: a randomized trial.
Bazzano LA, Hu T, Reynolds K, Yao L, Bunol C, Liu Y, Chen CS, Klag MJ, Whelton PK, He J.

Abstract

BACKGROUND:
Low-carbohydrate diets are popular for weight loss, but their cardiovascular effects have not been well-studied, particularly in diverse populations.

OBJECTIVE:
To examine the effects of a low-carbohydrate diet compared with a low-fat diet on body weight and cardiovascular risk factors.

DESIGN:
A randomized, parallel-group trial. (ClinicalTrials.gov: NCT00609271).

SETTING:
A large academic medical center.

PARTICIPANTS:
148 men and women without clinical cardiovascular disease and diabetes.

INTERVENTION:
A low-carbohydrate (<40 g/d) or low-fat (<30% of daily energy intake from total fat [<7% saturated fat]) diet. Both groups received dietary counseling at regular intervals throughout the trial.

MEASUREMENTS:
Data on weight, cardiovascular risk factors, and dietary composition were collected at 0, 3, 6, and 12 months.

RESULTS:
Sixty participants (82%) in the low-fat group and 59 (79%) in the low-carbohydrate group completed the intervention. At 12 months, participants on the low-carbohydrate diet had greater decreases in weight (mean difference in change, -3.5 kg [95% CI, -5.6 to -1.4 kg]; P = 0.002), fat mass (mean difference in change, -1.5% [CI, -2.6% to -0.4%]; P = 0.011), ratio of total-high-density lipoprotein (HDL) cholesterol (mean difference in change, -0.44 [CI, -0.71 to -0.16]; P = 0.002), and triglyceride level (mean difference in change, -0.16 mmol/L [-14.1 mg/dL] [CI, -0.31 to -0.01 mmol/L {-27.4 to -0.8 mg/dL}]; P = 0.038) and greater increases in HDL cholesterol level (mean difference in change, 0.18 mmol/L [7.0 mg/dL] [CI, 0.08 to 0.28 mmol/L {3.0 to 11.0 mg/dL}]; P < 0.001) than those on the low-fat diet.

LIMITATION:
Lack of clinical cardiovascular disease end points.

CONCLUSION:
The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Restricting carbohydrate may be an option for persons seeking to lose weight and reduce cardiovascular risk factors.

 

[adreno]

And how about its effects on the microbiome (and subsequently the immune system)?

 

[alex3619]

And how about its effects on the microbiome (and subsequently the immune system)?

I have no idea but I think this is a good question. Altering the gut nutrients should shift the microbiome ecology substantially.

 

[maddietod]

I'm in the midst of figuring out what balance of carbs-fats-sugars makes me feel best, while still feeding my gut. I think the fat vs. carbs issue is only useful to people trying to sell diet books. It's not either-or, in my experience.

In terms of weight loss, what works for me is fish, moderate meats, and carbs from non-starchy vegetables and small amounts of fruit. Fats are in the proteins, sugars are in the vegetables and occasional fruits. Eating carbs + sugar is my formula for weight gain.

Over time this dietary pattern should create healthy changes in my gut. I help that along with an emphasis on prebiotic foods and probiotic supplementation.

On the other hand, I tested the 'potato diet' last week, with my weight-loss pattern already firmly in place. Eating literally nothing but potato (180g carbs), I lost a pound overnight. Unfortunately I also confirmed my suspected potato allergy and had to abort the test.

So, again, I think carbs vs. fat is a useless paradigm. I think it's all about balance, and those ratios are different for each of us.

 

[MeSci]

I have no idea but I think this is a good question. Altering the gut nutrients should shift the microbiome ecology substantially.

Well, leaky-gut diets involve reducing carbs, especially sugar. Mine has definitely improved my gut function. I only have to eat one extra apple a day (2 instead of 1) to cause a deterioration in gut function. Shame, as my tree produces the most delicious apples and they don't keep very well!

 

[Sidereal]

And how about its effects on the microbiome (and subsequently the immune system)?

There hasn't been a huge amount of work done in this area but what little has been done suggests very bad news. Anecdotally, the paleo and low carb online communities are littered with casualties of long-term diets of this nature which restrict fermentable substrates for the microbiota.

I used to moderate a low carb forum. This stuff was commonplace and usually attributed to other factors like "adrenal fatigue" because short-term effects of these diets are often very beneficial so once they stop working, people can't understand what is happening.

Speaking personally, I was mildly sick long before embarking on very low carb diets but it wasn't until I did that I crashed completely and experienced a total metabolic collapse and became bedridden/housebound. It's a pity because low carb diets are highly effective for weight loss and glucose/insulin control in the short-term. Of course, it wasn't until much later that I began to appreciate (thanks to this forum) that these problems originate in gut dysbiosis. Butyrate is absolutely critical to health.

@Vegas and @Ripley have written about this quite a bit on the RS thread.

http://www.ncbi.nlm.nih.gov/pubmed/21389180

Am J Clin Nutr. 2011 May;93(5):1062-72. doi: 10.3945/ajcn.110.002188. Epub 2011 Mar 9.
High-protein, reduced-carbohydrate weight-loss diets promote metabolite profiles likely to be detrimental to colonic health.
Russell WR1, Gratz SW, Duncan SH, Holtrop G, Ince J, Scobbie L, Duncan G, Johnstone AM, Lobley GE,Wallace RJ, Duthie GG, Flint HJ.
Author information

Abstract
BACKGROUND:
Diets that are high in protein but reduced in carbohydrate contents provide a common approach for achieving weight loss in obese humans. However, the effect of such diets on microbiota-derived metabolites that influence colonic health has not been established.

OBJECTIVE:
We designed this study to assess the effect of diets with reduced carbohydrate and increased protein contents on metabolites considered to influence long-term colonic health, in particular the risk of colorectal disease.

DESIGN:
We provided 17 obese men with a defined weight-maintenance diet (85 g protein, 116 g fat, and 360 g carbohydrate/d) for 7 d followed by 4 wk each of a high-protein and moderate-carbohydrate(HPMC; 139 g protein, 82 g fat, and 181 g carbohydrate/d) diet and a high-protein and low-carbohydrate (HPLC; 137 g protein, 143 g fat, and 22 g carbohydrate/d) diet in a crossover design. Fecal samples were analyzed to determine concentrations of phenolic metabolites, short-chain fatty acids, and nitrogenous compounds of dietary and microbial origin.

RESULTS:
Compared with the maintenance diet, the HPMC and HPLC diets resulted in increased proportions of branched-chain fatty acids and concentrations of phenylacetic acid and N-nitroso compounds. The HPLC diet also decreased the proportion of butyrate in fecal short-chain fatty acid concentrations, which was concomitant with a reduction in the Roseburia/Eubacterium rectale group of bacteria, and greatly reduced concentrations of fiber-derived, antioxidant phenolic acids such as ferulate and its derivatives.

CONCLUSIONS:
After 4 wk, weight-loss diets that were high in protein but reduced in totalcarbohydrates and fiber resulted in a significant decrease in fecal cancer-protective metabolites and increased concentrations of hazardous metabolites. Long-term adherence to such diets may increase risk of colonic disease.

http://www.ncbi.nlm.nih.gov/pubmed/17189447

Appl Environ Microbiol. 2007 Feb;73(4):1073-8. Epub 2006 Dec 22.
Reduced dietary intake of carbohydrates by obese subjects results in decreased concentrations of butyrate and butyrate-producing bacteria in feces.
Duncan SH1, Belenguer A, Holtrop G, Johnstone AM, Flint HJ, Lobley GE.
Author information

Abstract
Weight loss diets for humans that are based on a high intake of protein but low intake of fermentablecarbohydrate may alter microbial activity and bacterial populations in the large intestine and thus impact on gut health. In this study, 19 healthy, obese (body mass index range, 30 to 42) volunteers were given in succession three different diets: maintenance (M) for 3 days (399 g carbohydrate/day) and then high protein/medium (164 g/day) carbohydrate (HPMC) and high protein/low (24 g/day)carbohydrate (HPLC) each for 4 weeks. Stool samples were collected at the end of each dietary regimen. Total fecal short-chain fatty acids were 114 mM, 74 mM, and 56 mM (P < 0.001) for M, HPMC, and HPLC diets, respectively, and there was a disproportionate reduction in fecal butyrate (18 mM, 9 mM, and 4 mM, respectively; P < 0.001) with decreasing carbohydrate. Major groups of fecal bacteria were monitored using nine 16S rRNA-targeted fluorescence in situ hybridization probes, relative to counts obtained with the broad probe Eub338. No significant change was seen in the relative counts of the bacteroides (Bac303) (mean, 29.6%) or the clostridial cluster XIVa (Erec482, 23.3%), cluster IX (Prop853, 9.3%), or cluster IV (Fprau645, 11.6%; Rbro730 plus Rfla729, 9.3%) groups. In contrast, the Roseburia spp. and Eubacterium rectale subgroup of cluster XIVa (11%, 8%, and 3% for M, HPMC, and HPLC, respectively; P < 0.001) and bifidobacteria (4%, 2.1%, and 1.9%, respectively; P = 0.026) decreased as carbohydrate intake decreased. The abundance of butyrate-producing bacteria related to Roseburia spp. and E. rectale correlated well with the decline in fecalbutyrate.

 

[MeSci]

There hasn't been a huge amount of work done in this area but what little has been done suggests very bad news. Anecdotally, the paleo and low carb online communities are littered with casualties of long-term diets of this nature which restrict fermentable substrates for the microbiota.

I used to moderate a low carb forum. This stuff was commonplace and usually attributed to other factors like "adrenal fatigue" because short-term effects of these diets are often very beneficial so once they stop working, people can't understand what is happening.

Speaking personally, I was mildly sick long before embarking on very low carb diets but it wasn't until I did that I crashed completely and experienced a total metabolic collapse and became bedridden/housebound. It's a pity because low carb diets are highly effective for weight loss and glucose/insulin control in the short-term. Of course, it wasn't until much later that I began to appreciate (thanks to this forum) that these problems originate in gut dysbiosis. Butyrate is absolutely critical to health.

@Vegas and @Ripley have written about this quite a bit on the RS thread.

http://www.ncbi.nlm.nih.gov/pubmed/21389180

http://www.ncbi.nlm.nih.gov/pubmed/17189447

I agree absolutely that very low carb is a bad idea and that it is vital to consume fermentable substances. I limit grains and sugar but have plenty of veg and a small amount of fruit.

I'm not sure what the subjects in the study I cited consumed, but <40g carb does sound low.

I followed the original resistant starch thread and learned a lot from it, including the connections between good fermentable starch and mood by optimising the pathway leading to serotonin as opposed to kynurenine, which enabled me to choose the effective mood supplement 5-HTP for the low mood I was suffering (not due to diet).

 

[Sidereal]

I agree absolutely that very low carb is a bad idea and that it is vital to consume fermentable substances. I limit grains and sugar but have plenty of veg and a small amount of fruit.

I'm not sure what the subjects in the study I cited consumed, but <40g carb does sound low.

I followed the original resistant starch thread and learned a lot from it, including the connections between good fermentable starch and mood by optimising the pathway leading to serotonin as opposed to kynurenine, which enabled me to choose the effective mood supplement 5-HTP for the low mood I was suffering (not due to diet).

I would be curious to see what they actually ate in this study (i.e. what compliance was like with the <40g carb/day recommendation, if this was measured). I haven't seen the full text but in some longitudinal studies of this type (and in the real world, I should say), participants experience carb creep and the longer they are followed up, the more moderate carb their diet becomes. Often the abstracts are misleading because when you look at what they actually ate at the six or twelve-month follow-up, it's 100+ grams of carb a day. The same applies to alleged low fat diets in these studies. Most of the time the "low fat" group only manages to decrease their fat intake by a few percent of the total daily calorie intake.

Lack of compliance is a notable "problem" in diet studies. Perhaps lack of compliance actually protects people from the deleterious long-term effects of very low carb intake.

 

[cman89]

Many ketogenic diet effects have been shown to be positive for some neural disorders, and perhaps other pain disorders, so I am dunno on this. I know that the key is to reduce inflammation, and over fermentation in the gut is as bad as under fermentation. Cutting out gluten and for many people dairy can do wonders. Can still be moderate carb, even with a fruit decrease