Johanna Conrad

Dr. Johanna Conrad


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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16 February 2024 in Critical Reviews in Food Science and Nutrition
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Journal Article
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JBJanett Barbaresko
Janett Barbaresko
JBJanine Bröder
Janine Bröder
JCJohanna Conrad
Johanna Conrad
ESEdyta Szczerba
Edyta Szczerba
ALAlexander Lang
Alexander Lang
SSSabrina Schlesinger
Sabrina Schlesinger
Recently, ultra-processed foods received a lot of attention, but also criticism. Our aim was to provide an overview of the existing evidence of ultra-processed food consumption on human health. We conducted a systematic search in four databases until January 5th, 2024. Systematic reviews with meta-analyses on ultra-processed food consumption as defined by the NOVA classification system were included. The certainty of evidence was evaluated by the GRADE approach. We identified 16 publications. Moderate certainty of evidence was found for all-cause mortality (Summary Risk Ratio per 50 g: 1.02; 95% confidence Interval (CI): 1.01, 1.03), cardiovascular disease incidence and mortality (per 50 g/d: 1.04; 95% CI: 1.02, 1.06, and 1.05; 95% CI: 1.01, 1.08), type 2 diabetes incidence (per 10%: 1.12; 95% CI: 1.10, 1.13) and colorectal cancer (per 10%: 1.04; 95% CI: 1.01, 1.07). For several outcomes such as inflammatory bowel diseases, obesity, metabolic syndrome, nonalcoholic fatty liver disease, mental health as well as nutrient quality, similar estimates were observed, but certainty of evidence was limited. Discussing the NOVA concept, it remains unclear whether the processing of foods leads to increased health risks or if ultra-processed food consumption is only a measure for poor diet quality.

6 February 2017 in Proceedings of the Nutrition Society
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JCJohanna Conrad
Johanna Conrad
UNUte Nöthlings
Ute Nöthlings
Valid estimation of usual dietary intake in epidemiological studies is a topic of present interest. The aim of the present paper is to review recent literature on innovative approaches focussing on: (1) the requirements to assess usual intake and (2) the application in large-scale settings. Recently, a number of technology-based self-administered tools have been developed, including short-term instruments such as web-based 24-h recalls, mobile food records or simple closed-ended questionnaires that assess the food intake of the previous 24 h. Due to their advantages in terms of feasibility and cost-effectiveness these tools may be superior to conventional assessment methods in large-scale settings. New statistical methods have been developed to combine dietary information from repeated 24-h dietary recalls and FFQ. Conceptually, these statistical methods presume that the usual food intake of a subject equals the probability of consuming a food on a given day, multiplied by the average amount of intake of that food on a typical consumption day. Repeated 24-h recalls from the same individual provide information on consumption probability and amount. In addition, the FFQ can add information on intake frequency of rarely consumed foods. It has been suggested that this combined approach may provide high-quality dietary information. A promising direction for estimation of usual intake in large-scale settings is the integration of both statistical methods and new technologies. Studies are warranted to assess the validity of estimated usual intake in comparison with biomarkers.

6 January 2020 in Nutrients
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Journal Article
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SKStefanie Koch
Stefanie Koch
JCJohanna Conrad
Johanna Conrad
LHLinda Hierath
Linda Hierath
NHNeil Hancock
Neil Hancock
SBSarah Beer
Sarah Beer
UNUte Nöthlings
Ute Nöthlings
Our aim was to develop and evaluate a German adaptation of myfood24, a fully automated, web-based 24-h dietary recall (24HDR). To complete a self-administered 24HDR with myfood24, users have to search and enter consumed foods within the underlying database by a free text search. The adaptation process thus mainly consisted of the development of an appropriate food database. myfood24-Germany was evaluated in 92 adults aged 17–78 years (study 1). Participants completed four non-consecutive 24HDRs and answered an evaluation questionnaire after the final recall. The System Usability Scale Score (SUS Score, 0–100) was calculated. Users’ search behavior was examined with screen recordings in 15 adults aged 20–60 years (study 2). Participants had to enter three sample meals presented as food packaging or pictures. The final database included 11,501 food items (7203 generic and 4298 branded items) with up to 131 nutrients. In study 1, the median completion time for a 24HDR was 15 min. The median SUS score of 78 indicated good usability. The majority of participants considered the overall user-friendliness as good (46%) or very good (21%), and 75% were willing to use myfood24-Germany regularly. Both studies showed that finding and choosing an appropriate item within the database was a major challenge. A German version of myfood24 was successfully developed. The user evaluation indicated a short completion time, good usability and acceptability of the tool, and confirmed its feasibility for repeated short-term application.

11 May 2021 in European Journal of Nutrition
Verified
Journal Article
Open access
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SKStefanie Koch
Stefanie Koch
JCJohanna Conrad
Johanna Conrad
JCJanet Cade
Janet Cade
LWLeonie Weinhold
Leonie Weinhold
UAUte Alexy
Ute Alexy
UNUte Nöthlings
Ute Nöthlings
Purpose: We aimed to validate myfood24-Germany, a web-based 24-h dietary recall (24HDR), by comparing its performance with a weighed dietary record (WDR) and biomarkers. Methods: 97 adults (77% female) completed a 3-day WDR with a 24-h urine collection on day 3, followed by at least one 24HDR with myfood24-Germany (corresponding to day 3 of the WDR). Intake of energy and 32 nutrients assessed by myfood24-Germany and the WDR for the same day were compared (method comparison). Intakes of protein and potassium assessed by myfood24-Germany/WDR were compared with intake estimated from urinary biomarkers for protein and potassium (biomarker comparison). Results: In the method comparison, significant correlations were found for energy and all tested nutrients (range 0.45–0.87). There was no significant difference between both methods in the assessed mean energy and macronutrient intake. However, myfood24-Germany underestimated mean intake of 15 nutrients. In the biomarker comparison, protein intake reported by myfood24-Germany/WDR was on average 10%/8% lower than estimated by biomarker. There was no significant difference in mean potassium intake assessed by myfood24-Germany/WDR and biomarker. However, a shared bias in the assessment of potassium intake was observed for both instruments. Concordance correlation coefficients (pc) and weighted Kappa coefficients (κ) confirmed good agreement with the biomarker estimates for myfood24-Germany/WDR in case of protein (pc = 0.58/0.66, κ = 0.51/0.53) and moderate agreement in case of potassium (pc = 0.44/0.51; κ = 0.30/0.33). Conclusion: Our results suggest that myfood24-Germany is of comparable validity to traditional dietary assessment methods.

1 September 2018 in Current Opinion in Clinical Nutrition and Metabolic Care
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Journal Article
Closed access
JCJohanna Conrad
Johanna Conrad
SKStefanie Koch
Stefanie Koch
UNUte Nöthlings
Ute Nöthlings
Purpose of reviewA promising direction for improving dietary intake measurement in epidemiologic studies is the combination of short-term and long-term dietary assessment methods using statistical methods. Thereby, web-based instruments are particularly interesting as their application offers several potential advantages such as self-administration and a shorter completion time. The objective of this review is to provide an overview of new web-based short-term instruments and to describe their features.Recent findingsA number of web-based short-term dietary assessment tools for application in different countries and age-groups have been developed so far. Particular attention should be paid to the underlying database and the search function of the tool. Moreover, web-based instruments can improve the estimation of portion sizes by offering several options to the user.SummaryWeb-based dietary assessment methods are associated with lower costs and reduced burden for participants and researchers, and show a comparable validity with traditional instruments. When there is a need for a web-based tool researcher should consider the adaptation of existing tools rather than developing new instruments. The combination of short-term and long-term instruments seems more feasible with the use of new technology.

10 February 2025 in JMIR Human Factors
Verified
Journal Article
Open access
LKLinda Klasen
Linda Klasen
SKStefanie Koch
Stefanie Koch
MBMaike Elena Benz
Maike Elena Benz
JCJohanna Conrad
Johanna Conrad
UAUte Alexy
Ute Alexy
UNUte Nöthlings
Ute Nöthlings
Background: Repeated applications of short-term dietary assessment instruments are recommended for estimating usual dietary intake. For this purpose, NutriDiary, a smartphone app for collecting weighed dietary records (WDRs) in the German population, was developed. Objective: We aim to describe NutriDiary and evaluate its usability and acceptability. Methods: NutriDiary was developed as a WDR, allowing users to enter food items via text search, barcode scanning, or free text entry. The sample for the evaluation study included 74 participants (n=51, 69% female, aged 18‐64 years), including 27 (37.5%) experts and 47 (63.5%) laypersons (including n=22, 30%, nutrition students). Participants completed a 1-day WDR and entered a predefined sample meal (n=17 foods) the following day by using NutriDiary. An evaluation questionnaire was answered from which the system usability scale (SUS) score (0‐100) was calculated. A backward selection procedure (PROC REG in SAS; SAS Institute) was used to identify potential predictors for the SUS score (age, sex, status [expert or laypersons], and operating system [iOS or Android]). Results: The median SUS score of 75 (IQR 63‐88) indicated good usability. Age was the only characteristic identified as a potential predictor for a lower SUS score (P<.001). The median completion time for an individual WDR was 35 (IQR 19‐52) minutes. Older participants took longer to enter the data than younger ones (18‐30 y: median 1.5, IQR 1.1‐2.0 min/item vs 45‐64 y: median 1.8, IQR 1.3‐2.3 min/item). Most participants expressed a preference for NutriDiary over the traditional paper-based method. Conclusions: Good usability and acceptability make NutriDiary promising for use in epidemiological studies.