From Theory to Practice: Nutrient Timing and Meal Frequency in Women Across Life Stages – An Exploratory Analysis
- Denis Keck
- Dec 18, 2025
- 5 min read
As a fitness scientist and nutritional diagnostician following the Erpse methodology, I have dedicated my bachelor's thesis to a topic that has long been neglected in nutritional science: How do meal frequency and the timing of food intake affect women in different life stages? The results of my exploratory study provide some exciting initial clues – and at the same time raise important questions for the future.
Why is this topic so important?
Body composition – the ratio of fat mass, muscle mass, and body water – is a central health indicator. It not only influences the risk of chronic diseases such as type 2 diabetes and cardiovascular complications, but also affects performance, quality of life, and healthy aging.
While we have long focused primarily on the quantity and quality of nutrients in nutritional science, timing is increasingly gaining importance. Nutrient Timing refers to the targeted temporal control of food intake to optimize physiological processes such as insulin sensitivity, muscle protein synthesis, and fat distribution.
It becomes particularly interesting when we introduce meal frequency – the number of meals per day – into the equation. Here, the research literature is controversial: while earlier recommendations focused on multiple small meals, current studies show that the relationships are more complex and depend heavily on individual factors such as age, gender, and lifestyle.
The Central Research Gap: Women in Different Life Stages
A crucial factor in examining nutritional strategies is age – especially in women. Women of reproductive age (20-40 years) show greater metabolic flexibility than women after menopause (from approximately 60 years old). After menopause, estrogen levels drop significantly, which is associated with a redistribution of body fat toward visceral fat, a decline in muscle mass (sarcopenia), and reduced bone mineral density.
Despite these demonstrated relevances, there is a lack of studies that systematically investigate how nutrient timing and meal frequency affect body composition in an age- and gender-specific manner. Previous research has often focused on young adults or men – a direct comparison between premenopausal and postmenopausal women has rarely been conducted.
My Study: Design and Methodology
This is precisely where my bachelor's thesis came in. The central research question was:
Does a structured increase in meal frequency to 5 meals daily result in measurable changes in body composition in pre- and postmenopausal women – and do these effects differ between life stages?
The study included 9 women (5 premenopausal, 4 postmenopausal). After a one-week familiarization phase in which participants documented their usual eating habits, there was a four-week intervention phase. Participants increased their meal frequency from an average of 3-4 to 5 meals per day – with largely constant calorie intake.
Body composition was measured using bioelectrical impedance analysis (BIA) and caliper measurements. Nutrition was documented via the Nutrilize app – an important detail: participants had no insight into their calorie or macronutrient values to avoid unconscious behavior. Physical activity was to remain constant throughout the study period.
The Results: First Exciting Findings
Analysis of the data revealed differentiated changes between the two groups:
Significant Group Differences
Postmenopausal women showed – as expected – a higher body fat percentage (42.5% vs. 31.6%) and significantly increased abdominal skinfold thickness (35.3 mm vs. 19.6 mm) compared to premenopausal women. These differences were statistically significant and reflect known hormonal changes.
Fat Mass Reduction Despite Isocaloric Diet
Particularly interesting: both groups showed a reduction in fat mass – even though calorie intake remained constant. The postmenopausal group showed a stronger decrease with -2.22 kg compared to the premenopausal group with -0.77 kg. This time effect was statistically significant (p = 0.049).
Maintenance and Increase of Lean Mass
At the same time, both groups showed a slight increase in lean mass (musculature): premenopausal +0.47 kg, postmenopausal +0.92 kg. This is particularly significant for older women, as age-related muscle mass loss is exacerbated by hormonal changes.
High Adherence
Participants implemented the intervention very successfully: the premenopausal group achieved 97% adherence, the postmenopausal group even 103% (some women occasionally ate 6 instead of 5 meals).
How Can the Results Be Explained?
The fact that changes in body composition occurred despite constant calorie intake suggests metabolic adaptations that go beyond simple energy balance concepts. Possible mechanisms include:
Thermogenesis: More frequent meals can influence the thermic effect of food.
Optimized Protein Distribution: More even protein distribution throughout the day can promote muscle protein synthesis – especially in older adults suffering from "anabolic resistance."
Hormonal Regulation: More frequent meals can modulate the profile of hunger and satiety hormones such as ghrelin and GLP-1.
Chrononutrition: The temporal structuring of food intake can influence circadian rhythms and the expression of CLOCK and BMAL1 genes.
Critical Assessment: What the Study Does NOT Show
As a scientist, it is important for me to clearly state the limitations of my study:
Small Sample Size: With only 9 participants, statistical power is limited. A power analysis would have required at least 36 participants.
Short Intervention Duration: The four-week intervention captures only short-term effects. Long-term impacts remain unknown.
Lack of Control Group Design: Without a comparison group, confounding factors cannot be completely ruled out.
Exploratory Nature: The study primarily serves hypothesis generation – not the derivation of clinical recommendations.
A particularly impressive example of the limitations of small samples: one participant showed a weight gain (+1.4 kg) and fat mass increase (+2.54 kg) – even though she adhered to the intervention protocol. Analysis revealed that she worked in shift work. Shift work is associated with a 23-25% increased risk of overweight in meta-analyses and illustrates how external stressors can massively influence individual outcomes.
My Conclusion and Outlook
My bachelor's thesis provides first exploratory evidence that a structured increase in meal frequency can produce measurable changes in body composition even without calorie reduction – particularly in postmenopausal women. The results are interesting enough to justify further scientific investigation, but not sufficient to already derive concrete practical recommendations.
What is Needed for the Future?
Randomized controlled trials with larger sample sizes (≥64 per group) and longer durations (≥12 weeks)
Integration of biomarkers (cortisol, leptin, ghrelin, insulin)
Consideration of confounding factors such as chronotype, shift work, and stress levels
Investigation of the role of the gut microbiome in mediating meal frequency effects
Societal Relevance
Given demographic development and the rising prevalence of metabolic disorders in postmenopausal women, structured nutritional interventions – once appropriately scientifically validated – could in the future contribute to the development of evidence-based prevention strategies.
My Work in the Context of Nutritional Diagnostics
As a fitness scientist, I work with the Nutritional Diagnostics approach from the Erpse Institute Switzerland. This holistic approach combines nutrition, movement, and psychological elements and uses measurable and verifiable data to identify metabolic bottlenecks and weaknesses in the body.
The insights from my bachelor's thesis underscore the need for individualized, life-stage-specific nutritional concepts. What works for a 30-year-old woman doesn't necessarily have to be optimal for a 65-year-old woman. This is precisely where nutritional diagnostics comes in: through precise measurements, individual analysis, and evidence-based strategies.
If you have questions about the study or personalized nutritional counseling, I'm happy to help!
Denis Keck, B.A. Fitness Science and Fitness Economics
