Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Metabolic States of the Body: Fasting and Starvation01:24

Metabolic States of the Body: Fasting and Starvation

1.5K
During the initial hours of fasting, the body uses up its glycogen stores as an energy source. Once these glycogen reserves are depleted, the body begins breaking down stored triglycerides and structural proteins. During this stage, glycerol becomes a key substrate for gluconeogenesis, while free fatty acids undergo beta-oxidation to provide energy for tissues, such as skeletal muscle. In the fasting state, the body spares protein breakdown as much as possible to conserve muscle and structural...
1.5K
Metabolic States of the Body: The Postabsorptive State01:18

Metabolic States of the Body: The Postabsorptive State

367
The postabsorptive state usually starts about four hours after a meal and lasts until the next meal is eaten. During this time, the digestive system stops absorbing nutrients, and the body uses stored energy reserves to maintain stable blood glucose levels.
Initially, glycogen stored in the liver is broken down to release glucose into the bloodstream, while glycogen in the muscles is broken down to supply glucose for energy directly within the muscle cells. As glycogen stores diminish,...
367
Metabolic States of the Body: The Absorptive State01:25

Metabolic States of the Body: The Absorptive State

718
During the absorptive state, which lasts approximately four hours after a meal, the body absorbs nutrients from the gastrointestinal tract. The carbohydrates, proteins, and lipids we consume are broken down into monosaccharides, amino acids, and free fatty acids for absorption. While carbohydrates and proteins are absorbed as-is, lipids are absorbed in their broken-down forms and then re-esterified into triglycerides within enterocytes before being packaged into chylomicrons. These absorbed...
718

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Metabolomic signatures of ideal cardiovascular health in black adults.

Scientific reports·2024
Same author

Protein S-palmitoylation enhances profibrotic signaling in response to cadmium.

Toxicology and applied pharmacology·2024
Same author

Pharmacometabolomics in TB Meningitis - understanding the pharmacokinetic, metabolic, and immune factors associated with anti-TB drug concentrations in cerebrospinal fluid.

medRxiv : the preprint server for health sciences·2024
Same author

Dioxin(-like)-Related Biological Effects through Integrated Chemical-wide and Metabolome-wide Analyses.

Environmental science & technology·2023
Same author

The neonatal blood spot metabolome in retinoblastoma.

EJC paediatric oncology·2023
Same author

Untargeted serum metabolomics reveals novel metabolite associations and disruptions in amino acid and lipid metabolism in Parkinson's disease.

Molecular neurodegeneration·2023
Same journal

Different approaches of strength-to-muscle mass ratio: impact on 24-month outcomes in patients with acute coronary syndrome.

Nutrition (Burbank, Los Angeles County, Calif.)·2026
Same journal

From scriptural reference to scientific evidence a critical review of the nutritional composition and functional food potential of foods described in classical Islamic texts.

Nutrition (Burbank, Los Angeles County, Calif.)·2026
Same journal

Integrating BIA-derived body composition parameters with GLIM criteria for survival prediction in patients with solid tumors.

Nutrition (Burbank, Los Angeles County, Calif.)·2026
Same journal

Polyunsaturated fatty acids in the prevention, treatment, and survival of breast cancer.

Nutrition (Burbank, Los Angeles County, Calif.)·2026
Same journal

Unpacking the eating pathways: The mediating roles of emotional eating and problem-solving skills in the relationship between childhood trauma and eating expectancies.

Nutrition (Burbank, Los Angeles County, Calif.)·2026
Same journal

Improving communication about dietary fats: development and validation of the Fats-Related Attitude Scale based on data from Brazil, China, Croatia, Poland, and Spain.

Nutrition (Burbank, Los Angeles County, Calif.)·2026
See all related articles

Related Experiment Video

Updated: Jul 19, 2025

Author Spotlight: Illuminating New Avenues for Adipose Tissue Metabolism and Disease Prevention
02:55

Author Spotlight: Illuminating New Avenues for Adipose Tissue Metabolism and Disease Prevention

Published on: October 6, 2023

1.4K

Characterizing substrate utilization during the fasted state using plasma high-resolution metabolomics.

Kaitlin R Taibl1, Moriah P Bellissimo2, Matthew Ryan Smith3

  • 1Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States.

Nutrition (Burbank, Los Angeles County, Calif.)
|August 11, 2023
PubMed
Summary
This summary is machine-generated.

High-resolution metabolomics identified numerous plasma metabolites and 13 metabolic pathways linked to substrate utilization in fasted adults. This reveals key metabolic insights into nutrient use during fasting states.

Keywords:
EnergyIndirect calorimetryMetabolismMetabolomicsNutritionSubstrate utilization

More Related Videos

Analyzing Ex Vivo Metabolic Flux in Splenic and Cardiac Macrophages and Bone Marrow Monocytes
06:26

Analyzing Ex Vivo Metabolic Flux in Splenic and Cardiac Macrophages and Bone Marrow Monocytes

Published on: March 28, 2025

345
Liquid Chromatography Coupled to Refractive Index or Mass Spectrometric Detection for Metabolite Profiling in Lysate-based Cell-free Systems
14:42

Liquid Chromatography Coupled to Refractive Index or Mass Spectrometric Detection for Metabolite Profiling in Lysate-based Cell-free Systems

Published on: September 23, 2021

4.9K

Related Experiment Videos

Last Updated: Jul 19, 2025

Author Spotlight: Illuminating New Avenues for Adipose Tissue Metabolism and Disease Prevention
02:55

Author Spotlight: Illuminating New Avenues for Adipose Tissue Metabolism and Disease Prevention

Published on: October 6, 2023

1.4K
Analyzing Ex Vivo Metabolic Flux in Splenic and Cardiac Macrophages and Bone Marrow Monocytes
06:26

Analyzing Ex Vivo Metabolic Flux in Splenic and Cardiac Macrophages and Bone Marrow Monocytes

Published on: March 28, 2025

345
Liquid Chromatography Coupled to Refractive Index or Mass Spectrometric Detection for Metabolite Profiling in Lysate-based Cell-free Systems
14:42

Liquid Chromatography Coupled to Refractive Index or Mass Spectrometric Detection for Metabolite Profiling in Lysate-based Cell-free Systems

Published on: September 23, 2021

4.9K

Area of Science:

  • Metabolomics
  • Human Physiology
  • Nutritional Science

Background:

  • High-resolution metabolomics offers a global view of metabolites and pathways in physiological processes.
  • Substrate utilization during fasting is a key metabolic state, clinically assessed by respiratory exchange ratio (RER).

Purpose of the Study:

  • To utilize metabolomics to identify metabolic pathways and plasma metabolites associated with substrate utilization in healthy, fasted adults.
  • To explore the relationship between RER and the fasting plasma metabolome.

Main Methods:

  • A cross-sectional study involving 33 healthy adults after an overnight fast.
  • Indirect calorimetry was used to measure resting respiratory exchange ratio (RER).
  • Untargeted metabolomics on plasma samples using dual-column liquid chromatography and ultra-high-resolution mass spectrometry.

Main Results:

  • Respiratory exchange ratio (RER) was significantly associated with 1389 metabolites within 13 metabolic pathways (P < 0.05).
  • Key pathways identified include fatty acid activation, C21-steroid hormone biosynthesis, butyrate metabolism, carnitine shuttle, glucogenic amino acids, methionine and cysteine metabolism, galactose, and pyrimidine metabolism.
  • These findings highlight the involvement of lipid, amino acid, and carbohydrate metabolism in substrate utilization.

Conclusions:

  • The fasting plasma metabolome reflects diverse macronutrient pathways in healthy adults.
  • Metabolomics can provide insights into individual nutrient requirements.
  • Further research should compare these findings in clinical populations.