Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men

Author’s abstract:

Background: The carbohydrate–insulin model of obesity posits that habitual consumption of a high-carbohydrate diet sequesters fat within adipose tissue because of hyperinsulinemia and results in adaptive suppression of energy expenditure (EE). Therefore, isocaloric exchange of dietary carbohydrate for fat is predicted to result in increased EE, increased fat oxidation, and loss of body fat. In contrast, a more conventional view that “a calorie is a calorie” predicts that isocaloric variations in dietary carbohydrate and fat will have no physiologically important effects on EE or body fat.

Objective: We investigated whether an isocaloric low-carbohydrate ketogenic diet (KD) is associated with changes in EE, respiratory quotient (RQ), and body composition.

Design: Seventeen overweight or obese men were admitted to metabolic wards, where they consumed a high-carbohydrate baseline diet (BD) for 4 wk followed by 4 wk of an isocaloric KD with clamped protein. Subjects spent 2 consecutive days each week residing in metabolic chambers to measure changes in EE (EEchamber), sleeping EE (SEE), and RQ. Body composition changes were measured by dual-energy X-ray absorptiometry. Average EE during the final 2 wk of the BD and KD periods was measured by doubly labeled water (EEDLW).

Results: Subjects lost weight and body fat throughout the study corresponding to an overall negative energy balance of ∼300 kcal/d. Compared with BD, the KD coincided with increased EEchamber (57 ± 13 kcal/d, P = 0.0004) and SEE (89 ± 14 kcal/d, P < 0.0001) and decreased RQ (−0.111 ± 0.003, P < 0.0001). EEDLWincreased by 151 ± 63 kcal/d (P = 0.03). Body fat loss slowed during the KD and coincided with increased protein utilization and loss of fat-free mass.

Conclusion: The isocaloric KD was not accompanied by increased body fat loss but was associated with relatively small increases in EE that were near the limits of detection with the use of state-of-the-art technology. This trial was registered at clinicaltrials.gov as NCT01967563.

Exploring the relationship between preferences for high fat foods and efficacy of the ketogenic and modified Atkins diets among children with seizure disorders

This abstract is available at Pubmed.gov:

PURPOSE:

Previous research has indicated that children with seizures may prefer high fat foods – a preference compatible with ketogenic and modified Atkins dietary therapies. The purpose of this prospective study was to examine the relationship between fat preference and efficacy of therapeutic diets in treating intractable seizures among a pediatric population.

METHODS:

Preference for high fat foods was directly assessed in a sample of 30 children prior to commencing either the ketogenic or modified Atkins diet. Seizure control was assessed at 1, 3, 6, and 12 months following diet initiation. Using an intent-to-treat analysis, correlations between fat preference and diet efficacy were examined at each follow-up and across the follow-up period.

RESULTS:

At individual follow-ups, correlations between fat preference and diet efficacy varied in terms of both strength and significance; however, modest, positive correlations with fat preference were significant when examining high levels of efficacy (100% seizure reduction, ≥90% seizure reduction) across a 1-year follow-up period.

CONCLUSION:

These findings provide preliminary evidence that fat preference, when directly assessed, may be a useful predictor of treatment efficacy for the ketogenic and modified Atkins diets; however, further research is necessary.

Ketogenic diet in pediatric patients with refractory focal status epilepticus

This abstract is published on Pubmed.gov:

The ketogenic diet (KD) has been used as an alternative treatment for patients with refractory status epilepticus (SE).

PURPOSE:

In this retrospective study we assess the efficacy and tolerability of the KD in patients with refractory SE.

METHODS:

Between March 1, 2010 and January 1, 2014, 10 patients who met the diagnostic criteria of refractory SE seen at our department were placed on the KD and followed for a minimum of 6 months.

RESULTS:

Ketonuria was reached within 2-4 days (mean 3 days) for all patients. Seizures stopped in two patients and five patients had a 50-75% seizure reduction within 2-5 days (mean 2.5 days) following the onset of ketonuria and within 5-7 days (mean 5 days) following the onset of the diet. Three patients had a <50% seizure reduction and all of them had severe adverse events so the diet was discontinued. Seven patients remained on the diet for 6 months to 3 years (mean 1.5 years). In all seven patients within 4 months the seizures recurred, but their quality of life did not worsen. The frequency of the seizures consisted of weekly seizures in two, monthly seizures in two, occasional seizures in two, and isolated seizures in one. All of them kept a good tolerability of the diet.

CONCLUSION:

The KD is an effective and well-tolerated treatment option for patients with refractory SE. In patients with focal SE secondary to inflammatory or probably inflammatory diseases, the KD should be considered earlier in the course of the treatment.

Migraine improvement during short lasting ketogenesis: a proof-of-concept study

This abstract is published on Pubmed.gov:

BACKGROUND AND PURPOSE:

Ketogenesis is a physiological phenomenon due to starvation or a ketogenic diet (KD), a drastic restricted carbohydrate dietary regimen that induces lipid metabolism and ketone body synthesis. Two patients whose migraines disappeared only during, and not outside, cycles of very-low-calorie KD performed to reduce their weight were recently observed. To confirm our observation, in a dietitian clinical setting two parallel groups of migraineurs, one receiving a 1-month very-low-calorie KD prescription followed by a 5-month standard low-calorie diet (SD) and the other a 6-month SD, were followed.

METHODS:

Ninety-six overweight female migraineurs were enrolled in a diet clinic and blindly received a KD (n = 45) or an SD (n = 51) prescription. Mean monthly attack frequency, number of days with headaches and tablet intake were assessed before and 1, 2, 3 and 6 months after diet initiation.

RESULTS:

In the KD group, the baseline attack frequency (2.9 attacks per month), number of days with headaches (5.11 days per month) and tablet intake (4.91 doses per month) were significantly reduced after the first month of diet (respectively 0.71, 0.91, 0.51; overall, KD versus baseline, P < 0.0001). During the transition period (first versus second month), the KD group showed a transient worsening of each clinical headache variable (respectively 2.60, 3.60, 3.07), despite being improved compared with baseline, with continuous improvement up to month 6 (respectively 2.16, 2.78, 3.71). In the SD group, significant decreases in the number of days with headaches and tablet intake were observed only from month 3 (P < 0.0001), and in attack frequency at month 6 (P < 0.0001).

CONCLUSIONS:

The underlying mechanisms of KD efficacy could be related to its ability to enhance mitochondrial energy metabolism and counteract neural inflammation.

A decade of the modified Atkins diet (2003–2013): Results, insights, and future directions

The modified Atkins diet has been used since 2003 for the treatment of children and adults with refractory epilepsy.This “alternative” ketogenic diet is started in clinic, without fasting, hospitalization, and restriction of protein,calories, or fluid intake. Now after 10 years of continued use, approximately 400 patients have been reported in over 30 studies of the modified Atkins diet as treatment for intractable seizures, with results demonstrating similar efficacy to the ketogenic diet and improved tolerability. The modified Atkins diet is being increasingly used in the adult population. Clinical trials have provided insight into the mechanisms of action of dietary therapies overall. This review will discuss the past decade of experience with the modified Atkins diet as well as predictions for its role in the treatment of epilepsy a decade from now.

Long Term Successful Weight Loss with a Combination Biphasic Ketogenic Mediterranean Diet and Mediterranean Diet Maintenance Protocol

Weight loss protocols can only be considered successful if they deliver consistent results over the long term—a goal which is often elusive, so much so that the term “yo-yo” is used to describe the perennial weight loss/weight regain battle common in obesity. We hypothesized that a ketogenic Mediterranean diet with phytoextracts (KEMEPHY) combined with the acknowledged health benefits of traditional Mediterranean nutrition may favor long term weight loss. We analysed 89 male and female obese subjects, aged between 25 and 65 years who were overall healthy apart from being overweight. The subjects followed a staged diet protocol over a period of 12 months: 20 day of KEMEPHY; 20 days low carb-non ketogenic; 4 months Mediterranean normocaloric nutrition; a second 20 day
ketogenic phase followed by 6 months of Mediterranean normocaloric nutrition. For the majority of subjects (88.25%) there was significant loss of weight (from 100.7 ± 16.54 to 84.59 ± 9.71 kg; BMI from 35.42 ± 4.11 to 30.27 ± 3.58) and body fat (form 43.44% ± 6.34% to 33.63% ± 7.6%) during both ketogenic phases followed by successful maintenance, without weight regain, during the 6 month stabilization phase with only 8 subjects failing to comply. There were also significant and stable decreases in total cholesterol, LDLc, triglycerides and glucose levels over the 12 month study period. HDLc showed small increases after the ketogenic phases but over the full 12 months there was no significant change. No significant changes were observed in ALT, AST, Creatinine or BUN. The combination of a biphasic KEMEPHY diet separated by longer periods of maintenance nutrition, based on the traditional Mediterranean diet, led to successful long term weight loss and improvements in health risk factors in a majority of subjects; compliance was very high which was a key determinant of the results seen.

A Pilot Study of a Low-Carbohydrate, Ketogenic Diet for Obesity-Related Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age, and is frequently associated with central obesity, insulin resistance, and dyslipidemia. Because recent evidence demonstrates that a low carbohydrate ketogenic diet (LCKD) leads to weight loss and improvements in insulin sensitivity, we conducted this uncontrolled trial of the diet for PCOS.

Effects of Two Weight-loss Diets on Health-related Quality of Life.

Mental aspects of HRQOL (health related quality of life) improved more in participants following an LCKD (low calorie ketogenic diet) than an LFD (low fat diet), possibly resulting from the LCKD’s composition, lack of explicit energy restriction, higher levels of satiety or metabolic effects. The factors analyzed were: Physical Functioning, Role-Physical, General Health, Vitality, Social Functioning. The Physical Component Summary score improved similarly in both diet groups. Bodily Pain improved in the LFD group only, whereas the Role-Emotional and Mental Health subscales and the Mental Component Summary (MCS) score improved in the LCKD group only.