Tobias Fischer

Prof. Dr. Tobias Fischer

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Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

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12 April 2018 in Journal of Nutrition and Metabolism
Verified
Journal Article
Open access
PDF file
TFTobias Fischer
Tobias Fischer
UOUlrike Och
Ulrike Och
IKIra Klawon
Ira Klawon
TOTim Och
Tim Och
MGMarianne Grüneberg
Marianne Grüneberg
TMThorsten Marquardt
Thorsten Marquardt
Background. Ketone body therapy and supplementation are of high interest for several medical and nutritional fields. The intake of ketone bodies is often discussed in relation to rare metabolic diseases, such as multiple acyl-CoA dehydrogenase deficiency (MADD), that have no alternatives for treatment. Case reports showed positive results of therapy using ketone bodies. The number of ketone body salts offered on the wellness market is increasing steadily. More information on the kinetics of intake, safety, and tolerance of these products is needed.Methods. In a one-dose kinetic study, six healthy subjects received an intervention (0.5 g/kg bw) using a commercially available ketone body supplement. The supplement contained a mixture of sodium and calcium D-/L-β-hydroxybutyrate (βHB) as well as food additives. The blood samples drawn in the study were tested for concentrations of D-βHB, glucose, and electrolytes, and blood gas analyses were done. Data on sensory evaluation and observed side effects of the supplement were collected. The product also went through chemical food analysis.Results. The supplement led to a significant increase of D-βHB concentration in blood 2.5 and 3 h after oral intake (p=0.033;  p=0.043). The first significant effect was measured after 2 h with a mean value of 0.598 ± 0.300 mmol/L at the peak, which was recorded at 2.5 h. Changes in serum electrolytes and BGA were largely unremarkable. Taking the supplement was not without side effects. One subject dropped out due to gastrointestinal symptoms and two others reported similar but milder problems.Conclusions. Intake of a combination of calcium and sodium D-/L-βHB salt shows a slow resorption with a moderate increase of D-βHB in serum levels. An influence ofβHB salts on acid-base balance could not be excluded by this one-dose study. Excessive regular consumption without medical observation is not free of adverse effects. The tested product can therefore not be recommended unconditionally.

24 February 2023 in Nutrients
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Journal Article
Open access
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CHChristina Heidt
Christina Heidt
MFManfred Fobker
Manfred Fobker
Mary NewportMary Newport
Mary Newport
RFReinhold Feldmann
Reinhold Feldmann
TFTobias Fischer
Tobias Fischer
TMThorsten Marquardt
Thorsten Marquardt
MCTs are increasingly being used to promote ketogenesis by patients on ketogenic diet therapy, but also by people with other conditions and by the general public for the perceived potential benefits. However, consumption of carbohydrates with MCTs and untoward gastrointestinal side effects, especially at higher doses, could decrease the sustainability of the ketogenic response. This single-center study investigated the impact of consuming carbohydrate as glucose with MCT oil compared to MCT alone on the BHB response. The effects of MCT oil versus MCT oil plus glucose on blood glucose, insulin response, levels of C8, C10, BHB, and cognitive function were determined, and side effects were monitored. A significant plasma BHB increase with a peak at 60 min was observed in 19 healthy participants (24.4 ± 3.9 years) after consuming MCT oil alone, and a more delayed but slightly higher peak was observed after consuming MCT oil plus glucose. A significant increase in blood glucose and insulin levels occurred only after MCT oil plus glucose intake. The overall mean plasma levels of C8 and C10 were higher with the intake of MCT oil alone. MCT oil plus glucose consumption showed improved scores for the arithmetic and vocabulary subtests.

1 April 2019 in Nutrition
Verified
Journal Article
Closed access
TFTobias Fischer
Tobias Fischer
UOUlrike Och
Ulrike Och
TMThorsten Marquardt
Thorsten Marquardt

15 June 2021 in Journal of Nutrition and Metabolism
Verified
Journal Article
Open access
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ABAnna Baumeister
Anna Baumeister
JGJoachim Gardemann
Joachim Gardemann
MFManfred Fobker
Manfred Fobker
VSVerena Spiegler
Verena Spiegler
TFTobias Fischer
Tobias Fischer
Background. Ketone bodies are a highly relevant topic in nutrition and medicine. The influence of medium-chain triglycerides (MCT) on ketogenesis is well known and has been successfully used in ketogenic diets for many years. Nevertheless, the effects of MCTs and coconut oil on the production of ketone bodies have only partially been investigated. Furthermore, the increased mobilisation of free fatty acids and release of catabolic hormones by caffeine suggest an influence of caffeine on ketogenesis. Methods. In a controlled, double-blind intervention study, seven young healthy subjects received 10 mL of tricaprylin (C8), tricaprin (C10), C8/C10 (50% C8, 50% C10), or coconut oil with or without 150 mg of caffeine, in 250 mL of decaffeinated coffee, over ten interventions. At baseline and after every 40 minutes, for 4 h, ßHB and glucose in capillary blood as well as caffeine in saliva were measured. Furthermore, questionnaires were used to survey sensory properties, side effects, and awareness of hunger and satiety. Results. The interventions with caffeine caused an increase in ßHB levels—in particular, the interventions with C8 highly impacted ketogenesis. The effect decreased with increased chain lengths. All interventions showed a continuous increase in hunger and diminishing satiety. Mild side effects (total = 12) occurred during the interventions. Conclusions. The present study demonstrated an influence of caffeine and MCT on ketogenesis. The addition of caffeine showed an additive effect on the ketogenic potential of MCT and coconut oil. C8 showed the highest ketogenicity.

8 May 2024 in Dietetics
Verified
Journal Article
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VBVanessa Böse
Vanessa Böse
MFMarius Frenser
Marius Frenser
MSMelanie Schumacher
Melanie Schumacher
TFTobias Fischer
Tobias Fischer
The importance of digital tools for dietary assessment has increased in recent years, both commercially and scientifically. In the field of nutrition research, the digitization of dietary assessment methods presents many opportunities and risks. One of the main challenges is ensuring scientific quality while maintaining good usability. In this context, an evaluation tool was developed based on the guidelines of the European Food Safety Authorization (EFSA; 2009 and 2014), complemented by the usability aspect of health-related applications. This was followed by a literature search concerning the available dietary assessment tools, which were analyzed according to the evaluation criteria. Eight applications were included in the study after reviewing the inclusion and exclusion criteria for the digital tools. A total of thirty-eight requirements in eight main categories were defined for the evaluation, which the best possible dietary assessment tool should meet. The evaluation showed that none of the tested tools currently meet all the defined requirements or categories. The aspects of usability and the accuracy of data collection showed a positive correlation, suggesting a direct link between the two categories and providing an important approach for future developments.

1 September 2019 in Molecular Genetics and Metabolism Reports
Verified
Journal Article
Open access
TFTobias Fischer
Tobias Fischer
CEChristiane Elpers
Christiane Elpers
UOUlrike Och
Ulrike Och
MFManfred Fobker
Manfred Fobker
TMThorsten Marquardt
Thorsten Marquardt
Multiple acyl-CoA dehydrogenase deficiency (MADD) is a severe inborn disorder of mitochondrial fatty acid oxidation. The only treatment option for MADD is the use of exogenous ketone bodies, like sodium β-hydroxybutyrate (NaβHB). However, the use of ketone body salts leads to a high intake of accompanying minerals, which can lead to additional side effects. The use of mineral-free formulations could improve tolerability. In this report, the use of a βHB acid (βHBA) in a patient with MADD is described. The production of D/L-βHBA was carried out using ion exchange chromatography (IEX) and using a precipitation method. During two inpatient treatment intervals, the tolerability as well as clinical and metabolic effects were monitored. D-βHB in serum, blood gas analysis, and standard blood measurements (like minerals) were used as control parameters. Production of D/L-βHBA using the precipitation method was more effective than using IEX. The tube feed solution used had a minimum pH of 3.5. Capillary D-βHB measurements were between 0.1 and 0.4 mmol/L and venous were at 0.1 mmol/L or below. Minerals and serum pH were within the normal range. During application of D/L-βHBA, gastrointestinal discomfort occurred and no clinical improvement was observed. The use of D/L-βHBA in the therapy of severe MADD could be a good addition to the use of classical ketone body salts. The observed gastrointestinal side effects were of a mild nature and could not be specifically attributed to the D/L-βHBA treatment. In short-term application, no clinical benefit and no substantial increase of D-βHB in serum were noted. No tendency towards acidosis or alkalosis was observed during the entire period of treatment.