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Spanish Ketogenic Mediterranean diet: a healthy cardiovascular diet for weight loss

  • Joaquín Pérez-Guisado1Email author,
  • Andrés Muñoz-Serrano1 and
  • Ángeles Alonso-Moraga1
Nutrition Journal20087:30

https://doi.org/10.1186/1475-2891-7-30

©  Pérez-Guisado et al; licensee BioMed Central Ltd. 2008

Received: 02 June 2008

Accepted: 26 October 2008

Published: 26 October 2008

Open Peer Review reports

Abstract

Background

Ketogenic diets are an effective healthy way of losing weight since they promote a non-atherogenic lipid profile, lower blood pressure and decrease resistance to insulin with an improvement in blood levels of glucose and insulin. On the other hand, Mediterranean diet is well known to be one of the healthiest diets, being the basic ingredients of such diet the olive oil, red wine and vegetables. In Spain the fish is an important component of such diet. The objective of this study was to determine the dietary effects of a protein ketogenic diet rich in olive oil, salad, fish and red wine.

Methods

A prospective study was carried out in 31 obese subjects (22 male and 19 female) with the inclusion criteria whose body mass index and age was 36.46 ± 2.22 and 38.48 ± 2.27, respectively. This Ketogenic diet was called "Spanish Ketogenic Mediterranean Diet" (SKMD) due to the incorporation of virgin olive oil as the principal source of fat (≥30 ml/day), moderate red wine intake (200–400 ml/day), green vegetables and salads as the main source of carbohydrates and fish as the main source of proteins. It was an unlimited calorie diet. Statistical differences between the parameters studied before and after the administration of the "Spanish Ketogenic Mediterranean diet" (week 0 and 12) were analyzed by paired Student's t test.

Results

There was an extremely significant (p < 0.0001) reduction in body weight (108.62 kg→ 94.48 kg), body mass index (36.46 kg/m2→31.76 kg/m2), systolic blood pressure (125.71 mmHg→109.05 mmHg), diastolic blood pressure (84.52 mmHg→ 75.24 mmHg), total cholesterol (208.24 mg/dl→186.62 mg/dl), triacylglicerols (218.67 mg/dl→113.90 mg/dl) and glucose (109.81 mg/dl→ 93.33 mg/dl). There was a significant (p = 0.0167) reduction in LDLc (114.52 mg/dl→105.95 mg/dl) and an extremely significant increase in HDLc (50.10 mg/dl→54.57 mg/dl). The most affected parameter was the triacylglicerols (47.91% of reduction).

Conclusion

The SKMD is safe, an effective way of losing weight, promoting non-atherogenic lipid profiles, lowering blood pressure and improving fasting blood glucose levels. Future research should include a larger sample size, a longer term use and a comparison with other ketogenic diets.

Background

The international consensus is that carbohydrates are the basis of the food pyramid for a healthy diet and that the best way to lose weight is by cutting back on calories chiefly in the form of fat. It is generally believed that ketogenic diets may lead to the development of several diseases. However, many studies have found that ketogenic diets are healthier since they help to preserve muscle mass, reduce appetite, diminish metabolic efficiency, induce metabolic activation of thermogenesis, favor increased fat loss, promote a non-atherogenic lipid profile, lower blood pressure and decrease resistance to insulin with an improvement in blood levels of glucose and insulin [1]. Contrary to past opinions, high carbohydrate diets may be associated with: low levels of high-density lipoprotein cholesterol (HDLc), high levels of triacylglycerols (TG), low-density lipoprotein cholesterol (LDLc) and total cholesterol [2], type 2 diabetes mellitus [3], metabolic syndrome, essential hypertension [4] and cancer [5].

Mediterranean diet has evident health benefits. Such diet is associated with a longer life span [6, 7] and lower rates of coronary heart disease, certain cancers [8], hypercholesterolemia, hypertension, diabetes and obesity [9]. It is difficult to define which are the healthiest constituents of the Mediterranean diet, since it is a very varied diet that can change among the Mediterranean countries. For example, in Spain the fish is an important component [10, 11] as well as the olive oil, red wine and vegetables, that are 3 essential components of such diet in all the countries. The healthy properties of the incorporation of olive oil, red wine and fish consumption to a ketogenic diet could be explained by the 3 following sections. Regarding the healthy properties of vegetables it is well known that they are high in water, phytonutrients, antioxidants and provide a good source of fiber.

The objective of the present study was to determine the dietary effects of the "Spanish Ketogenic Mediterranean Diet" (SKMD). Such diet was a protein ketogenic diet under free-living conditions with 4 important healthy components of the Mediterranean diet in Spain: olive oil, salad, fish and red wine. Therefore, the present study was carried out to demonstrate the changes in body weight, blood pressure, lipid profile and glucose that might occur after the administration of SKMD throughout the period of study (12 weeks), in healthy obese subjects.

Olive oil

Olive oil, is considered the pillar of the Mediterranean diet, since it improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed beside the monounsaturated fatty acids (MUFA) to the minor components of virgin olive oil [12]. Hydrocarbons, polyphenols, tocopherols, sterols, triterpenoids and other components, despite their low concentration, non-fatty acid constituents may be of importance because studies comparing monounsaturated dietary oils have reported different effects on cardiovascular disease. Most of these compounds have demonstrated antioxidant, anti-inflammatory and hypolipidemic properties [13]. Moreover, MUFA-rich diet prevents central fat redistribution and the postprandial decrease in peripheral adiponectin gene expression and insulin resistance induced by a carbohydrate-rich diet in insulin-resistant subjects [14].

Red wine

The combination of ethanol and phenolic compounds in red wine is thought to be responsible for the apparent protective cardiovascular effect [15], showing olive oil and red wine antioxidant polyphenols antiatherogenic properties [16]. Moreover, combined consumption of wine and olive oil provided beneficial postprandial effects on haemodynamics [17].

Fish

Two long-chain Omega-3 polyunsaturated fatty acids (n-3 PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are the active constituents of the fish. Low rates of death from coronary heart disease has been report among individuals with very high consumption of fish, although these people should limit intake of species highest in mercury levels. Larger, longer-living predators (swordfish, shark) have higher tissue concentrations, while smaller or shorter-lived species (anchovy, shellfish, salmon, sardine) have very low concentrations [18].

High omega-3 consumption increases insulin sensitivity and reduces inflammatory markers [19] and Piers et al. have hypothesized that unsaturated fats (MUFA and/or PUFA), rather than saturated fat (SFA), are more effective in stimulating peroxisome proliferator-activated receptor-α leading to fat oxidation, with SFA being much more readily diverted to fat storage [20].

Methods

Subjects

A prospective study was carried out at a General Medicine Consultation (Córdoba, Spain) in 40 overweight subjects (22 male and 19 female) whose body mass index and age was 36.46 ± 2.22 and 38.48 ± 2.27, respectively. Subjects were selected with the cooperation of a database medical weight loss clinic. Inclusion criteria were: a diet based on carbohydrate foods (> 50% of dairy energy intake), achievement of desired weight loss, normal liver and renal function, not to have antecedents of gout or high uric acid, not to have exercise, alcoholic and smoking habits, not to be pregnant or lactating, IMC ≥ 30, age ≥ 18 years and ≤ 65 years and not to be under medication. Since obesity increases the risk for alterations in hepatocyte function that lead to accumulation of lipid in hepatocytes and hepatomegaly (Non-alcoholic Fatty Liver Disease), we consider higher liver transaminase levels as a variant of normality in such obese patients (hepatic transaminases ≤ twice normal values → GOT and GPT ≤ 80 mU/ml). Chronic hepatitis B or C was ruled out in such patients by negative serologies. We determined normal renal function as measured by plasma urea nitrogen and plasma creatinine: creatinine ≤ 1.3 mg/dl and urea ≤ 40 mg/dl. Subjects with the inclusion criteria were selected for eligibility by phone and 40 eligible subjects were invited to attend an orientation session during the week prior to the study. Patients measured their body's ketosis state every morning by ketone strips. During the study, the participants were phoned by the same person weekly, in order to assure the correct realization of the protocol and the ketosis state. If the subjects failed to maintain adequate compliance with the clinical trial protocol they would be dropped out the study.

Subjects received no monetary compensation for their participation and provided voluntary written consent form before initiating the diet.

The Ethics and Clinical Investigation Committee of the "Spanish Medical Association of the Proteinic Diet" approved the study protocol, informed consent form and subject informational materials. Patient anonymity was preserved.

Diet

This protein ketogenic diet was called "Spanish Ketogenic Mediterranean Diet" (SKMD) due to the incorporation of virgin olive oil as the principal source of fat, moderate red wine intake, green vegetables and salads as the main source of carbohydrates and fish as the main source of proteins. It was an unlimited calorie diet, nevertheless subjects were encouraged to consume per day: a maximum of 30 g of carbohydrates in the form of green vegetables and salad, a minimum of 30 ml of virgin olive oil, 200–400 ml of red wine and no limit of the protein block.

Participants were permitted 3 portions (200 g/portion) of vegetables daily: 2 portions of salad vegetables (such as alfalfa sprouts, lettuce, escarole, endive, mushrooms, radicchio, radishes, parsley, peppers, chicory, spinach, cucumber, chard and celery), and 1 portion of low-carbohydrate vegetables (such as broccoli, cauliflower, cabbage, artichoke, eggplant, squash, tomato and onion). 3 portions of salad vegetables were allowed only if the portion of low-carbohydrate vegetables were not consumed. Salad dressing allowed were: garlic, olive oil, vinegar, lemon juice, salt, herbs and spices.

The minimum 30 ml of olive oil were distributed unless in 10 ml per principal meal (breakfast, lunch and dinner). Red wine (200–400 ml a day) was distributed in 100–200 ml per lunch and dinner. The protein block was divided in "fish block" and "no fish block". The "fish block" included all the types of fish except larger, longer-living predators (swordfish and shark). The "no fish block" included meat, fowl, eggs, shellfish and cheese. Both protein blocks were not mixed in the same day and were consumed individually during its day on the condition that at least 4 days of the week were for the "fish block".

Trans fats (margarines and their derivatives) and processed meats with added sugar were not allowed.

No more than two cups of coffee or tea and at least 3 litres of water were intake each day. Infusions and artificial sweeteners were allowed (saccharin, cyclamate, acesulfame, aspartame and sucralose).

Supplements

Micronutrients (vitamins and minerals) were given daily to each subject in the form of 2 tablets of a poly-vitamin-mineral supplement and one tablet of calcium carbonate 1500 mg. Each tablet of the poly-vitamin-mineral supplement contained: vitamin A 680 mcg, Beta-carotene 720 mcg, vitamin D 5 mcg, vitamin E 10 mg, vitamin C 60 mg, vitamin B1 1.4 mg, vitamin B2 1.6 mg, vitamin B6 2 mg, folic acid 200 mcg, vitamin B12 1 mcg, niacin 18 mg, biotin 150 mcg, pantothenic acid 6 mg, vitamin K 30 mcg, calcium 120 mg, potassium 40 mg, phosphorus 126.3 mcg, iron 8 mg, magnesium 45 mg, cupper 0.9 mg, zinc 8 mg, manganesum 1.8 mg, iodine 75 mcg, molibden 45 mcg, boron 70 mcg, chlorine 21 mg, chromium 25 mcg, molybdenum 45 mcg, nickel 5 mcg, selenium 55 mcg, silicon 3 mg, sin 10 mcg, vanadium 10 mcg.

Measurements

Subjects were weighed and systolic/diastolic blood pressure was measurement at weeks 0, 4, 8 and 12, at the same time (that depends on the subject) and using always the same digital scale ("Seca 703") and mercurial sphygmomanometer ("Labtron Model 03-225").

Fasting venous blood samples were collected at weeks 0 and 12 for total cholesterol, HDLc, LDLc, triacylglycerol and glucose. Venous blood samples for glucose, lipid and lipoprotein analysis were collected into EDTA-containing (1 g/l) tubes from all subjects after a 12 h overnight fast at the beginning of the study and at the end of each dietary period. Plasma was obtained by low-speed centrifugation for 15 min at 4°C within 1 h of venepuncture. Plasma cholesterol and TAG levels were determined by enzymatic techniques. HDL-cholesterol was determined after precipitation with fosfowolframic acid LDL-cholesterol concentration was calculated using the Friedewald formula. Plasma glucose was measured by the glucose oxidase method. To reduce interassay variation, plasma was stored at -80°C and analysed at the end of the study.

Statistical analysis

Statistical differences between the parameters before and after the administration of the SKMD (week 0 and 12) were analyzed by paired Student's t test with SPSS 12.0 (SPSS Inc., Chicago, IL, USA) and are expressed as mean ± standard error of the mean (SEM). The parameters studied were: weight, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol, HDLc, LDLc, triacylglycerol and glucose. Before the Student's t test, Kolmogorov-Smirnov and Shapiro-Wilk tests were used for testing normality and the assumption of homoscedasticity was determined with the F-Snedecor test.

Results

Subject attrition

Of the 40 persons who started the study, data collected from 31 subjects were used in the final analysis. Data were not use from 9 subjects: 3 subjects were withdrawn for failure to maintain adequate compliance with the clinical trial protocol; 4 subjects were lost to follow-up; 1 subject withdrew because he said the diet was too expensive; 1 subject was withdrawn due to suffer a polytraumatism car accident.

Parameters analyzed

Normal distribution and the assumption of homoscedasticity were verified. As there were no significant differences in male and female subjects in all the parameters examined (p > 0.05), the data of males and females in each group are pooled and presented together. The changes in all the parameters studied are shown in Table 1.
Table 1

Changes in the level of various parameters before and after the SKMD

Parameters

Week 0*

Week 12*

% of Change

P

Weight (kg)

108.62 ± 3.18

94.48 ± 2.83

13.02

<0.0001

BMI (kg/m2)

36.46 ± 0.84

31.76 ± 0.74

12.89

<0.0001

Total Cholesterol (mg/dl)

208.24 ± 5.86

186.62 ± 5.80

10.38

<0.0001

LDLc (mg/dl)

114.52 ± 6.17

105.95 ± 7.67

7.48

0.0167

HDLc (mg/dl)

50.10 ± 1.69

54.57 ± 1.50

8.19

<0.0001

Triacylglicerols (mg/dl)

218.67 ± 9.55

113.90 ± 5.20

47.91

<0.0001

Glycemia (mg/dl)

109.81 ± 2.22

93.33 ± 1.83

15.01

<0.0001

SBP (mm Hg)

125.71 ± 5.19

109.05 ± 4.41

13.25

<0.0001

DBP (mm Hg)

84.52 ± 2.76

75.24 ± 2.35

10.98

<0.0001

*Data are expressed as mean ± standard error of the mean (SEM).

There was an extremely significant (p < 0.0001) reduction in body weight (108.62 kg→ 94.48 kg), BMI (36.46 kg/m2→31.76 kg/m2), SBP (125.71 mmHg→109.05 mmHg), DBP (84.52 mmHg→ 75.24 mmHg), total cholesterol (208.24 mg/dl→186.62 mg/dl) and glucose (109.81 mg/dl→ 93.33 mg/dl). There was a significant (p = 0.0167) reduction in LDLc (114.52 mg/dl→105.95 mg/dl) and an extremely significant increase in HDLc (50.10 mg/dl→54.57 mg/dl).

Discussion

Weight loss

It is thought that consumption of a high-fat-protein diet will be accompanied by a higher weight gain. On the contrary, our results confirm that the SKMD is an effective therapy for obesity without caloric restriction. This might be due to the fact that there is a synergic effect between the high protein ketogenic nature of the diet and its richness in MUFA and PUFA. We don't have data about the percentage of body fat and lean body mass lost. Nevertheless we think that there was a more selective fat loss because we didn't observe the flaccidity physical aspect that we have observed before with hypocaloric diets, and subjects had a physical aspect similar to a liposuction, since fat was removed from many different fat specific deposit areas, including the abdomen, thighs, hips, buttocks, waist, neck and upper arms. Our hypothesis is founded in the following statements:

1. Many studies have confirmed that the ketogenic diet is an effective therapy for obesity [1, 21–26]. In addition to the fact that an equal number of calories are ingested, ketogenic diets are more effective for achieving fat loss than the conventional high-carbohydrate/low-fat diets [1, 26]. Low-carbohydrate diets have even proved to be more effective than conventional diets for more selective fat loss and conserving muscle mass [1, 24–26], moreover, several longer term studies have noted improvements in body composition on a higher protein pattern despite similar weight loss [27].

2. MUFA-rich diet prevents central fat redistribution [14].

3. High unsaturated fat diet is more effective to preserve lean mass than a low fat diet or a low carbohydrate diet [23]. Moreover, the PUFA from the fish, DHA and EPA exhibit "anti-obesity" effect as well as improving insulin sensitivity [28].

In connection with the moderate red wine consumption of the SKMD, we agree with the statement that moderate red wine consumption (450 ml) is not associated with differences in body weight [29], so this consumption would not affect to the weight loss.

Further trials are required to examine the potential role of the SKMD for the selective fat loss and its protective effect against muscle protein catabolism.

Glycemic control

During the SKMD the fasting glycemia improved significantly. These findings could be explained by the following points:

1. A low carbohydrate diet reduces fasting glucose levels, even independently of the weight loss [30, 31].

2. MUFA-rich diet prevents insulin resistance induced by a carbohydrate-rich diet in insulin-resistant subjects [14].

3. DHA-EPA also improve insulin sensitivity [28].

Our data are not enough to state with precision if the SKMD is the same or better than a conventional ketogenic diet to improve glycemic control due to its higher content in MUFA and DHA-EPA.

We think that the moderate prandial red wine consumption of the SKMD did not have effect (beneficial or adverse) on the glycemic control, since Gin et al. reported that moderate prandial wine consumption has no adverse effect on the glycemic control of diabetic patients, thus it appears unnecessary to proscribe the consumption of red wine in moderation with meals to diabetic patients [32].

Effects of the "Spanish Ketogenic Mediterranean diet" on cardiovascular parameters

The data presented in this study showed that the SKMD significantly decreases the total cholesterol, LDLc, triacylglycerols, SBP, DBP and increases the level of HDLc. This healthy cardiovascular profile is probably due to the favorable interaction of the weight loss and the components of the SKMD: high protein ketogenic diet-virgin olive oil-fish oil-red wine-salad. Our arguments are founded in the following findings:

1. Ketogenic diets improve all aspects of atherogenic dyslipidemia, decreasing fasting and postprandial triglyceride levels and increasing HDLc and LDLc particle size [1, 33]. When the ketogenic diet is higher in protein than fat, the level of LDLc also decreases [33–35].

2. Ingestion of virgin olive oil increases HDLc levels [36] and decreases LDLc levels [37–39] and blood pressure [38, 39].

3. Omega-3 PUFA reduce plasma triacylglycerol concentrations [40, 41].

4. Chronic moderate consumption of red wine (400 ml/day) significantly reduces fasting LDLc and increases HDLc in hypercholesterolaemic patients [42].

5. Low carbohydrate/high-protein diets are more effective than high-carbohydrate diets for decreasing blood pressure, both diastolic and systolic [43].

6. The salad consumption is inversely associated with diastolic blood pressure [44].

Explanations and Suggestions

We recognize several limitations of our study that may have influenced the study findings:

1. The sample of the study is small (31 subjects).

2. This is not a random population study, since subjects were selected for eligibility and their eligibility was related with their compliance to the diet.

3. Weight loss may be related with improvement in all parameters that are studied.

4. We didn't take into consideration calories intake before and after the 12 weeks. Although it is known that an equal number of calories are ingested, ketogenic diets are more effective for achieving fat loss than the conventional high-carbohydrate/low-fat diets [1, 26], we don't know if our patients intake less food and calories, and if it is the case, this would be correlated with weigh reduction and better cardiovascular parameters.

5. Although the effect of vitamins is not clear, especially in short interventions, their possible contribution to better cardiovascular parameters should be possible.

6. Our study has no control groups to consider the interaction between the components of the SKMD. There is no way to say if the healthy results are due to the ketogenic nature of the diet, the virgin olive oil, the red wine, the higher fish intake, the higher salad intake or a synergic effect between these components.

All these limitations should be known and accordingly considered by further trials.

Conclusion

The SKMD is safe, an effective way of losing weight, promoting non-atherogenic lipid profiles, lowering blood pressure and improving fasting blood glucose levels. Future research should include a larger sample size, a longer term use and a comparison with other ketogenic diets.

Abbreviations

EPA: 

eicosapentaenoic acid

DHA: 

docosahexaenoic acid

HDLc: 

high-density lipoprotein cholesterol

LDLc: 

low-density lipoprotein cholesterol

MUFA: 

monounsaturated fatty acids

PUFA: 

polyunsaturated fatty acids

SFA: 

saturated fat

SKMD: 

Spanish Ketogenic Mediterranean Diet

TG: 

triacylglycerols.

Declarations

Acknowledgements

The authors thank the men and women who participated in this investigation.

Authors’ Affiliations

(1)
Department of Genetic, University of Córdoba

References

  1. Pérez-Guisado J: Arguments In Favor Of Ketogenic Diets. Internet J Nutr Wellness. 2007, 4: 2-[http://www.ispub.com/ostia/index.php?xmlFilePath=journals/ijnw/vol4n2/diet.xml]Google Scholar
  2. Liu S, Manson JE, Stampfer MJ, Holmes MD, Hu FB, Hankinson SE, Willet WC: Dietary glycemic load assessed by food-frequency questionnaire in relation to plasma high-density-lipoprotein cholesterol and fasting plasma triacylglycerols in postmenopausal women. Am J Clin Nutr. 2001, 73: 560-566.PubMedGoogle Scholar
  3. Halton TL, Liu S, Manson JE, Hu FB: Low-carbohydrate-diet score and risk of type 2 diabetes in women. Am J Clin Nutr. 2008, 87: 339-346.PubMedPubMed CentralGoogle Scholar
  4. Kopp W: Pathogenesis and etiology of essential hypertension: role of dietary carbohydrate. Med Hypotheses. 2005, 64: 782-787. 10.1016/j.mehy.2004.10.009.View ArticlePubMedGoogle Scholar
  5. Pérez-Guisado J: Carbohydrates, glucose metabolism and cancer. Endocrinol Nutr. 2006, 53: 252-255. [http://external.doyma.es/pdf/12/12v53n04a13086356pdf001.pdf]View ArticleGoogle Scholar
  6. Trichopoulou A, Kouris-Blazos A, Wahlqvist M, Gnardellis C, Lagiou P, Polychronopoulos E, Vassilakou T, Lipworth L, Tricopoulos D: Diet and overall survival in elderly people. Br Med J. 1995, 311: 1457-60.View ArticleGoogle Scholar
  7. Osler M, Schroll M: Diet and mortality in a cohort of elderly people in a north European community. Int J Epidemiol. 1997, 26: 155-159. 10.1093/ije/26.1.155.View ArticlePubMedGoogle Scholar
  8. Willett WC, Sacks F, Trichopoulou A, Drescher G, Ferro-Luzzi A, Helsing E, Trichopoulou D: Mediterranean diet pyramid: a cultural model for healthy eating. Am J Clin Nutr. 1995, 61 (6 Suppl): 1402S-1406S.PubMedGoogle Scholar
  9. Panagiotakos DB, Polystipioti A, Papairakleous N, Polychronopoulos E: Long-term adoption of a Mediterranean diet is associated with a better health status in elderly people; a cross-sectional survey in Cyprus. Asia Pac J Clin Nutr. 2007, 16: 331-337.PubMedGoogle Scholar
  10. Álvarez-Sala LA, Millán J, De Oya M: La dieta mediterránea en España. ¿Leyenda o realidad? (II). Otros elementos de la dieta mediterránea: verdura y fruta, el pescado. Evolución de la dieta y de las enfermedades cardiovasculares en España en las últimas décadas. Rev Clin Esp. 1996, 196: 636-646.Google Scholar
  11. Moreiras-Varela O: The Mediterranean diet in Spain. Eur J Clin Nutr. 1989, 43 (Suppl 2): 83-87.PubMedGoogle Scholar
  12. Perez-Jimenez F, Alvarez de Cienfuegos G, Badimon L, Barja G, Battino M, Blanco A, Bonanome A, Colomer R, Corella-Piquer D, Covas I, Chamorro-Quiros J, Escrich E, Gaforio JJ, Garcia Luna PP, Hidalgo L, Kafatos A, Kris-Etherton PM, Lairon D, Lamuela-Raventos R, Lopez-Miranda J, Lopez-Segura F, Martinez-Gonzalez MA, Mata P, Mataix J, Ordovas J, Osada J, Pacheco-Reyes R, Perucho M, Pineda-Priego M, Quiles JL, Ramirez-Tortosa MC, Ruiz-Gutierrez V, Sanchez-Rovira P, Solfrizzi V, Soriguer-Escofet F, de la Torre-Fornell R, Trichopoulos A, Villalba-Montoro JM, Villar-Ortiz JR, Visioli F: International conference on the healthy effect of virgin olive oil. Eur J Clin Invest. 2005, 35: 421-424. 10.1111/j.1365-2362.2005.01516.x.View ArticlePubMedGoogle Scholar
  13. Perona JS, Cabello-Moruno R, Ruiz-Gutierrez V: The role of virgin olive oil components in the modulation of endothelial function. J Nutr Biochem. 2006, 17: 429-445. 10.1016/j.jnutbio.2005.11.007.View ArticlePubMedGoogle Scholar
  14. Paniagua JA, Gallego de la Sacristana A, Romero I, Vidal-Puig A, Latre JM, Sanchez E, Perez-Martinez P, Lopez-Miranda J, Perez-Jimenez F: Monounsaturated fat-rich diet prevents central body fat distribution and decreases postprandial adiponectin expression induced by a carbohydrate-rich diet in insulin-resistant subjects. Diabetes Care. 2007, 30: 1717-1723. 10.2337/dc06-2220.View ArticlePubMedGoogle Scholar
  15. Wollin SD, Jones PJH: Alcohol, red wine and cardiovascular disease. J Nutr. 2001, 131: 1401-1404.PubMedGoogle Scholar
  16. Carluccio MA, Siculella L, Ancora MA, Massaro M, Scoditti E, Storelli C, Visioli F, Distante A, De Caterina R: Olive Oil and Red Wine Antioxidant Polyphenols Inhibit Endothelial Activation: Antiatherogenic Properties of Mediterranean Diet Phytochemicals. Arterioscler Thromb Vasc Biol. 2003, 23: 622-629. 10.1161/01.ATV.0000062884.69432.A0.View ArticlePubMedGoogle Scholar
  17. Papamichael CM, Karatzi KN, Papaioannou TG, Karatzis EN, Katsichti P, Sideris V, Zakopoulos N, Zampelas A, Lekakis JP: Acute combined effects of olive oil and wine on pressure wave reflections: another beneficial influence of the Mediterranean diet antioxidants?. J Hypertens. 2008, 26: 223-229.View ArticlePubMedGoogle Scholar
  18. Mozaffarian D, Rimm EB: Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA. 2006, 296: 1885-1899. 10.1001/jama.296.15.1885.View ArticlePubMedGoogle Scholar
  19. Tsitouras PD, Gucciardo F, Salbe AD, Heward C, Harman SM: High Omega-3 Fat Intake Improves Insulin Sensitivity and Reduces CRP and IL6, but does not Affect Other Endocrine Axes in Healthy Older Adults. Horm Metab Res. 2008, 40: 199-205. 10.1055/s-2008-1046759.View ArticlePubMedGoogle Scholar
  20. Piers LS, Walker KZ, Stoney RM, Soares MJ, O'Dea K: Substitution of saturated with monounsaturated fat in a 4-week diet affects body weight and composition of overweight and obese men. Br J Nutr. 2003, 90: 717-727. 10.1079/BJN2003948.View ArticlePubMedGoogle Scholar
  21. Cassady BA, Charboneau NL, Brys EE, Crouse KA, Beitz DC, Wilson T: Effects of low carbohydrate diets high in red meats or poultry, fish and shellfish on plasma lipids and weight loss. Nutr Metab. 2007, 4: 23-10.1186/1743-7075-4-23.View ArticleGoogle Scholar
  22. Dashti HM, Al-Zaid NS, Mathew TC, Al-Mousawi M, Talib H, Asfar SK, Behbahani AI: Long Term Effects of Ketogenic Diet in Obese Subjects with High Cholesterol Level. Mol Cell Biochem. 2006, 286: 1-9. 10.1007/s11010-005-9001-x.View ArticlePubMedGoogle Scholar
  23. Noakes M, Foster PR, Keogh JB, James AP, Mamo JC, Clifton PM: Comparison of isocaloric very low carbohydrate/high saturated fat and high carbohydrate/low saturated fat diets on body composition and cardiovascular risk. Nutr Metab. 2006, 3: 7-10.1186/1743-7075-3-7.View ArticleGoogle Scholar
  24. Young CM, Scanlan SS, Im HS, Lutwak L: Effect on body composition and other parameters in obese young men of carbohydrate level of reduction diet. Am J Clin Nutr. 1971, 24: 290-296.PubMedGoogle Scholar
  25. Benoit FL, Martin RL, Watten RH: Changes in body composition during weight reduction in obesity: Balance studies comparing effects of fasting and a ketogenic diet. Ann Intern Med. 1965, 63: 604-612.View ArticlePubMedGoogle Scholar
  26. Pérez-Guisado J: Ketogenic diets and weight loss: basis and effectiveness. Arch Latinoam Nutr. 2008, 58: 126-131.PubMedGoogle Scholar
  27. Noakes M: The role of protein in weight management. Asia Pac J Clin Nutr. 2008, 17 (Suppl 1): 169-171.PubMedGoogle Scholar
  28. Li JJ, Huang CJ, Xie D: Anti-obesity effects of conjugated linoleic acid, docosahexaenoic acid, and eicosapentaenoic acid. Mol Nutr Food Res. 2008, 52 (6): 631-645. 10.1002/mnfr.200700399.View ArticlePubMedGoogle Scholar
  29. Beulens JW, van Beers RM, Stolk RP, Schaafsma G, Hendriks HF: The effect of moderate alcohol consumption on fat distribution and adipocytokines. Obesity. 2006, 14: 60-66. 10.1038/oby.2006.8.View ArticlePubMedGoogle Scholar
  30. Nielsen JV, Joensson E: Low-carbohydrate diet in type 2 diabetes. Stable improvement of bodyweight and glycemic control during 22 months follow-up. Nutr Metab. 2006, 3: 22-10.1186/1743-7075-3-22.View ArticleGoogle Scholar
  31. Boden G, Sargrad K, Homko C, Mozzoli M, Stein TP: Effects of a low- carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes. Ann Intern Med. 2005, 142: 403-411.View ArticlePubMedGoogle Scholar
  32. Gin H, Morlat P, Ragnaud JM, Aubertin J: Short-term effect of red wine (consumed during meals) on insulin requirement and glucose tolerance in diabetic patients. Diabetes Care. 1992, 1: 546-548. 10.2337/diacare.15.4.546.View ArticleGoogle Scholar
  33. Pérez-Guisado J: Ketogenic diets: additional benefits to the weight loss and unfounded secondary effects. Arch Latinoam Nutr.Google Scholar
  34. Dashti HM, Bo-Abbas YY, Asfar SK, Mathew TC, Hussein T, Behbahani A, Khoursheed MA, Al-Sayer HM, Al-Zaid NS: Ketogenic diet modifies the risk factors of heart disease in obese patients. Nutrition. 2003, 19: 901-902. 10.1016/S0899-9007(03)00161-8.View ArticlePubMedGoogle Scholar
  35. Dashti HM, Mathew TC, Khadada M, Al-Mousawi M, Talib H, Asfar SK, Behbahani AI, Al-Zaid NS: Beneficial effects of ketogenic diet in obese diabetic subjects. Mol Cell Biochem. 2007, 302: 249-256. 10.1007/s11010-007-9448-z.View ArticlePubMedGoogle Scholar
  36. Paniagua JA, de la Sacristana AG, Sánchez E, Romero I, Vidal-Puig A, Berral FJ, Escribano A, Moyano MJ, Peréz-Martinez P, López-Miranda J, Pérez-Jiménez F: A MUFA-rich diet improves posprandial glucose, lipid and GLP-1 responses in insulin-resistant subjects. J Am Coll Nutr. 2007, 26: 434-444.View ArticlePubMedGoogle Scholar
  37. Gimeno E, Fitó M, Lamuela-Raventós RM, Castellote AI, Covas M, Farré M, de La Torre-Boronat MC, López-Sabater MC: Effect of ingestion of virgin olive oil on human low-density lipoprotein composition. Eur J Clin Nutr. 2002, 56: 114-120. 10.1038/sj.ejcn.1601293.View ArticlePubMedGoogle Scholar
  38. Waterman E, Lockwood B: Active components and clinical applications of olive oil. Altern Med Rev. 2007, 12: 331-142.PubMedGoogle Scholar
  39. Covas MI: Olive oil and the cardiovascular system. Pharmacol Res. 2007, 55: 175-86. 10.1016/j.phrs.2007.01.010.View ArticlePubMedGoogle Scholar
  40. Roche HM, Gibney MJ: Effect of long-chain n-3 polyunsaturated fatty acids on fasting and postprandial triacylglycerol metabolism. Am J Clin Nutr. 2000, 71 (1 Suppl ): 232S-237S.PubMedGoogle Scholar
  41. Hartweg J, Perera R, Montori V, Dinneen S, Neil HA, Farmer A: Omega-3 polyunsaturated fatty acids (PUFA) for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2008, 1: CD003205-PubMedGoogle Scholar
  42. Naissides M, Mamo JC, James AP, Pal S: The effect of chronic consumption of red wine on cardiovascular disease risk factors in postmenopausal women. Atherosclerosis. 2006, 185: 438-445. 10.1016/j.atherosclerosis.2005.06.027.View ArticlePubMedGoogle Scholar
  43. Sargrad KR, Homko C, Mozzoli M, Boden G: Effect of high protein vs high carbohydrate intake on insulin sensitivity, body weight, hemoglobin A1c, and blood pressure in patients with type 2 diabetes mellitus. J Am Diet Assoc. 2005, 105: 573-580. 10.1016/j.jada.2005.01.009.View ArticlePubMedGoogle Scholar
  44. McNaughton SA, Ball K, Mishra GD, Crawford DA: Dietary patterns of adolescents and risk of obesity and hypertension. J Nutr. 2008, 138: 364-370.PubMedGoogle Scholar

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This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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