Giovanni Spera

Dr. Giovanni Spera

Department of Experimental Medicine, Section of Medical Pathophysiology, Food Science and Endocrinology, Sapienza University of Rome, 00161 Rome, Italy

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 January 2020 in Nutrients
Verified
Journal Article
Open access
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ABAdriano Bruci
Adriano Bruci
Dario TuccinardiDario Tuccinardi
Dario Tuccinardi
RTRossella Tozzi
Rossella Tozzi
ABAngela Balena
Angela Balena
SSSilvia Santucci
Silvia Santucci
Mikiko WatanabeMikiko Watanabe
Mikiko Watanabe
Very low-calorie ketogenic diets (VLCKD) are an effective and increasingly used tool for weight loss. Traditionally considered high protein, ketogenic diets are often looked at with concern by clinicians due to the potential harm they pose to kidney function. We herein evaluated the efficacy and safety of a VLCKD in patients with obesity and mild kidney failure. A prospective observational real-life study was conducted on ninety-two patients following a VLCKD for approximately 3 months. Thirty-eight had mild kidney failure and fifty-four had no renal condition and were therefore designated as control. Anthropometric parameters, bioelectrical impedance and biochemistry data were collected before and at the end of the dietary intervention. The average weight loss was nearly 20% of initial weight, with a significant reduction in fat mass. We report an improvement of metabolic parameters and no clinically relevant variation regarding liver and kidney function. Upon stratification based on kidney function, no differences in the efficacy and safety outcomes were found. Interestingly, 27.7% of patients with mild renal failure reported normalization of glomerular filtrate after dietary intervention. We conclude that, when conducted under the supervision of healthcare professionals, a VLCKD is an effective and safe treatment for weight loss in patients with obesity, including those affected by mild kidney failure.

9 May 2018 in Nutrients
Verified
Journal Article
Open access
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Mikiko WatanabeMikiko Watanabe
Mikiko Watanabe
EGElena Gangitano
Elena Gangitano
DFDavide Francomano
Davide Francomano
EAEliana Addessi
Eliana Addessi
RTRaffaella Toscano
Raffaella Toscano
Carla LubranoCarla Lubrano
Carla Lubrano
There is a widely acknowledged association between insulin resistance and obesity/type 2 diabetes (T2DM), and insulin sensitizing treatments have proved effective in preventing diabetes and inducing weight loss. Obesity and T2DM are also associated with increased inflammation. Mangosteen is a tropical tree, whose fruits—known for their antioxidant properties—have been recently suggested having a possible further role in the treatment of obesity and T2DM. The objective of this pilot study has been to evaluate safety and efficacy of treatment with mangosteen extract on insulin resistance, weight management, and inflammatory status in obese female patients with insulin resistance. Twenty-two patients were randomized 1:1 to behavioral therapy alone or behavioral therapy and mangosteen and 20 completed the 26-week study. The mangosteen group reported a significant improvement in insulin sensitivity (homeostatic model assessment-insulin resistance, HOMA-IR −53.22% vs. −15.23%, p = 0.004), and no side effect attributable to treatment was reported. Given the positive preliminary results we report and the excellent safety profile, we suggest a possible supplementary role of mangosteen extracts in the treatment of obesity, insulin resistance, and inflammation.

18 July 2020 in Nutrients
Verified
Journal Article
Open access
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Mikiko WatanabeMikiko Watanabe
Mikiko Watanabe
Renata RisiRenata Risi
Renata Risi
ECElisabetta Camajani
Elisabetta Camajani
SCSavina Contini
Savina Contini
APAgnese Persichetti
Agnese Persichetti
SBSabrina Basciani
Sabrina Basciani
Background: Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease. Very low-calorie ketogenic diets (VLCKD) represent a feasible treatment as they induce profound weight loss and insulin resistance (IR) improvement. Despite the recognized benefits on NAFLD deriving from pharmacological administration of fibroblast growth factor 21 (FGF21), whose endogenous counterpart is a marker of liver injury, little is known about its physiology in humans. Aim: To identify predictors of NAFLD improvement as reflected by the reduction of the non-invasive screening tool hepatic steatosis index (HSI) in obese patients undergoing a weight loss program. Methods: Sixty-five obese patients underwent a 90-day dietary program consisting of a VLCKD followed by a hypocaloric low carbohydrate diet (LCD). Anthropometric parameters, body composition, and blood and urine chemistry were assessed. Results: Unlike most parameters improving mainly during the VLCKD, the deepest HSI change was observed after the LCD (p = 0.02 and p < 0.0001, respectively). Baseline HOMA-IR and serum FGF21 were found to be positive (R = 0.414, p = 0009) and negative (R = 0.364, p = 0.04) independent predictors of HSI reduction, respectively. Conclusions: We suggest that patients with IR and NAFLD derive greater benefit from a VLCKD, and we propose a possible role of human FGF21 in mediating NAFLD amelioration following nutritional manipulation.

5 July 2021 in Nutrients
Verified
Journal Article
Open access
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Cherubino Di LorenzoCherubino Di Lorenzo
Cherubino Di Lorenzo
GBGiovanna Ballerini
Giovanna Ballerini
Piero BarbantiPiero Barbanti
Piero Barbanti
ABAndrea Bernardini
Andrea Bernardini
GDGiacomo D’arrigo
Giacomo D’arrigo
GSGiovanni Spera
Giovanni Spera
Headaches are among the most prevalent and disabling neurologic disorders and there are several unmet needs as current pharmacological options are inadequate in treating patients with chronic headache, and a growing interest focuses on nutritional approaches as non-pharmacological treatments. Among these, the largest body of evidence supports the use of the ketogenic diet (KD). Exactly 100 years ago, KD was first used to treat drug-resistant epilepsy, but subsequent applications of this diet also involved other neurological disorders. Evidence of KD effectiveness in migraine emerged in 1928, but in the last several year’s different groups of researchers and clinicians began utilizing this therapeutic option to treat patients with drug-resistant migraine, cluster headache, and/or headache comorbid with metabolic syndrome. Here we describe the existing evidence supporting the potential benefits of KDs in the management of headaches, explore the potential mechanisms of action involved in the efficacy in-depth, and synthesize results of working meetings of an Italian panel of experts on this topic. The aim of the working group was to create a clinical recommendation on indications and optimal clinical practice to treat patients with headaches using KDs. The results we present here are designed to advance the knowledge and application of KDs in the treatment of headaches.

28 March 2022 in Nutrients
Verified
Journal Article
Open access
PDF file
Davide MasiDavide Masi
Davide Masi
MSMaria Elena Spoltore
Maria Elena Spoltore
RRRebecca Rossetti
Rebecca Rossetti
Mikiko WatanabeMikiko Watanabe
Mikiko Watanabe
RTRossella Tozzi
Rossella Tozzi
Carla LubranoCarla Lubrano
Carla Lubrano
Chrononutrition is an emerging branch of chronobiology focusing on the profound interactions between biological rhythms and metabolism. This framework suggests that, just like all biological processes, even nutrition follows a circadian pattern. Recent findings elucidated the metabolic roles of circadian clocks in the regulation of both hormone release and the daily feeding–fasting cycle. Apart from serving as energy fuel, ketone bodies play pivotal roles as signaling mediators and drivers of gene transcription, promoting food anticipation and loss of appetite. Herein we provide a comprehensive review of the literature on the effects of the ketogenic diets on biological processes that follow circadian rhythms, among them appetite, sleep, and endocrine function.

1 March 2011 in The Journal of Sexual Medicine
Verified
Journal Article
Closed access
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Antonio AversaAntonio Aversa
Antonio Aversa
Massimiliano CaprioMassimiliano Caprio
Massimiliano Caprio
AAAntonella Antelmi
Antonella Antelmi
AAAndrea Armani
Andrea Armani
MBMarina Brama
Marina Brama
AFAndrea Fabbri
Andrea Fabbri