Wednesday, January 18, 2012

Low carb vs Keto

Here are two studies that shows it doesn't really matter what kind of diet you're on. All that really matters is energy deficit.



1: http://www.ncbi.nlm.nih.gov/pubmed/16476868

BACKGROUND:

Low-carbohydrate diets have become increasingly popular for weight loss. However, evidence from individual trials about benefits and risks of these diets to achieve weight loss and modify cardiovascular risk factors is preliminary.

METHODS:

We used the Cochrane Collaboration search strategy to identify trials comparing the effects of low-carbohydrate diets without restriction of energy intake vs low-fat diets in individuals with a body mass index (calculated as weight in kilograms divided by the square of height in meters) of at least 25. Included trials had to report changes in body weight in intention-to-treat analysis and to have a follow-up of at least 6 months. Two reviewers independently assessed trial eligibility and quality of randomized controlled trials.

RESULTS:

Five trials including a total of 447 individuals fulfilled our inclusion criteria. After 6 months, individuals assigned to low-carbohydrate diets had lost more weight than individuals randomized to low-fat diets (weighted mean difference, -3.3 kg; 95% confidence interval [CI], -5.3 to -1.4 kg). This difference was no longer obvious after 12 months (weighted mean difference, -1.0 kg; 95% CI, -3.5 to 1.5 kg). There were no differences in blood pressure. Triglyceride and high-density lipoprotein cholesterol values changed more favorably in individuals assigned to low-carbohydrate diets (after 6 months, for triglycerides, weighted mean difference, -22.1 mg/dL [-0.25 mmol/L]; 95% CI, -38.1 to -5.3 mg/dL [-0.43 to -0.06 mmol/L]; and for high-density lipoprotein cholesterol, weighted mean difference, 4.6 mg/dL [0.12 mmol/L]; 95% CI, 1.5-8.1 mg/dL [0.04-0.21 mmol/L]), but total cholesterol and low-density lipoprotein cholesterol values changed more favorably in individuals assigned to low-fat diets (weighted mean difference in low-density lipoprotein cholesterol after 6 months, 5.4 mg/dL [0.14 mmol/L]; 95% CI, 1.2-10.1 mg/dL [0.03-0.26 mmol/L]).

CONCLUSIONS:

Low-carbohydrate, non-energy-restricted diets appear to be at least as effective as low-fat, energy-restricted diets in inducing weight loss for up to 1 year. However, potential favorable changes in triglyceride and high-density lipoprotein cholesterol values should be weighed against potential unfavorable changes in low-density lipoprotein cholesterol values when low-carbohydrate diets to induce weight loss are considered.


2: http://www.ncbi.nlm.nih.gov/pubmed/18025815

BACKGROUND:

This study was designed to compare the effects of 2 different but isocaloric fat reduction programs with the same amount of energy deficit - diet alone or diet combined with aerobic training - on body composition, lipid profile and cardiorespiratory fitness in non- or moderately obese women.

METHODS:

Twenty non- or moderately obese (BMI 24.32 +/- 3.11) females (27.3 +/- 6.6 years) were tested at the beginning and after an 8-week period of a mild hypocaloric diet for the following parameters: (1) body mass and body fat; (2) total cholesterol, HDL-C, LDL-C and triglycerides; (3) lactate (millimol/liter) during submaximal exertion (100 W); (4) heart rate during submaximal exertion (100 W), and (5) maximum exercise performance (watt). Subjects were randomly divided into either a diet alone (D, -2,095 +/- 659 kJ/day) or a diet (-1,420 +/- 1,084 kJ/day) plus exercise (DE, three 60-min sessions per week at 60% of VO(2)max or -5,866 kJ/week) group.

RESULTS:

Body mass and body fat decreased significantly in D (-1.95 +/- 1.13 kg or -1.47 +/- 0.87%; p < 0.05) and DE (-2.23 +/- 1.28 kg or -1.59 +/- 0.87%; p < 0.05), but there was no significant difference observed between the groups. Statistical analysis revealed no significant changes of total cholesterol, HDL-C, LDL-C, triglycerides and heart rate during submaximal exertion (100 W). Lactic acid accumulation during submaximal exertion (100 W) decreased significantly (-0.8 +/- 1.4 mmol/l, p < 0.05) in DE and increased significantly (+0.4 +/- 0.5 mmol/l, p < 0.05) in D. Maximum exercise performance improved significantly (+12.2 +/- 8.8 W, p < 0.05) in DE and did not change significantly in D.

CONCLUSIONS:

This study showed that independently of the method for weight loss, the negative energy balance alone is responsible for weight reduction.



What we can draw from this is purely for losing weight, your diet doesn't matter. It only matters in regards to health. 
Calories in > x < Calories out

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