This a very good question. Since its discovery Leptin has been extensively studied as well as its hunger inhibition properties. A nice review on this topic was written by Farooqi et al (2014).
Link: Article Leptin at 20: An overview
Kratz et al. (2012) shows interesting findings between olive oil (rich in monounsaturated fatty acids, rapeseed oil (rich in monounsaturated fatty acids and α-linolenic acid) and sunflower oil (rich in n-6-polyunsaturated fatty acids) consumption and Leptin levels. The diets rich in unsaturated fatty acids induced changes in serum leptin concentrations, which were different for men and women. The article's references are rich of discussion of this topic.
Few researches can answer your question regarding intramuscular triglycerides. Leibel et al (1995) shows that the maintenance of a 10% or greater reduced body weight results in decreases in the energy cost of low levels of physical activity beyond those attributable to the altered body weight. These changes are due mainly to increased skeletal muscle work efficiency following weight loss and are reversed by the administration of the adipocyte-derived hormone leptin.
Baldwin et al (2011) published findings consistent with the leptin-reversible increase in skeletal muscle chemomechanical work efficiency and decrease in the ratio of glycolytic/oxidative enzyme activities observed in subjects that were following dietary weight loss. The maintenance of a reduced weight is accompanied by a decrease in ratio of glycolytic (phosphofructokinase) to oxidative (cytochrome c oxidase) activity in vastus lateralis muscle that would suggest an increase in the relative expression of the myosin heavy chain I (MHC I) isoform. However there is no further information about intramuscular triglycerides.
Link: Article Effects of weight loss and leptin on skeletal muscle in human subjects
Since the discovery of leptin there is a considerable amount of research has focused on leptin as a central regulator of body weight. In the animal model, research has demonstrated leptin action through hypothalamic centres altering both satiety and energy expenditure. In contrast to animal studies, it is unlikely that leptin functioning in the human system exerts such a profound role in body weight regulation. Human studies suggest that leptin levels are strongly correlated with both percentage fat mass and body mass index, in accordance with the proposed 'lipostatic theory'. It has been demonstrated that polyunsaturated fatty acid (PUFA) intake influences adipose tissue expression of leptin, and of several lipogenic enzymes and transcription factors. In addition, leptin stimulates triglyceride depletion in white adipose tissue without increasing free fatty acid release, thus favouring fatty acids versus glucose as a fuel source. Recent studies also suggest that the reduction in adipose hypertrophy observed with n-3 PUFA-containing fish oil feeding might involve a leptin-specific process. A large amount of evidence supports direct functioning of leptin in peripheral lipid metabolism in vivo and in vitro. It is possible that PUFAs will maintain an efficient level of circulating leptin, thus preventing leptin insensitivity and weight gain.
1. Janice K. Kiecolt-Glaser, Lisa M. Christian a,b,c , Rebecca Andridge d , Beom Seuk Hwang, William B. Malarkey, Martha A. Belury , Charles F. Emery, Ronald Glaser. Adiponectin, leptin, and yoga practice. Physiology & Behavior 107 (2012) 809–813
2. Aschbacher K, RodriguezFernandez M, van Wietmarschen H, Tomiyama AJ, Jain S, Epel E, Doyle III FJ, van der Greef J. 2014 The hypothalamic – pituitary – adrenal – leptin axis and metabolic health: a systems approach to resilience, robustness and control. Interface Focus 4: 20140020. http://dx.doi.org/10.1098/rsfs.2014.0020
3. Reynolds AC, Dorrian J, Liu PY, Van Dongen HPA, Wittert GA, Harmer LJ, et al. (2012) Impact of Five Nights of Sleep Restriction on Glucose Metabolism, Leptin and Testosterone in Young Adult Men. PLoS ONE 7(7): e41218. https://doi.org/10.1371/journal.pone.0041218
4. Clifton A. Baile and Mary Anne Della-Fera.REGULATION OF METABOLISM AND BODY FAT MASS BY LEPTIN; Annu. Rev. Nutr. 2000. 20:105–27
Could the Leptin be the key for weight loss and control? as well could the Leptin expression genes be the programmer for our weight and body configuration.
Thanks all. For me it was asked in relation to having low body fat percentage and keeping the fat metabolism healthy, by ingesting more fats, or the right fats, and by storing fat in muscle cells in the form of IMTG. So not really inter-muscular, because that is negative, but really in myocytes. So the negative effects of very low adipose fat I want to counter with storage in myocytes and improving dietary approaches. For instance if ALA can lead to higher leptin, a certain amount of fat is less needed. This because some athletes have low body fat and its unhealhty because they restrict themselves rather than improve diet ingestion. I will read the articles soon! Thanks
Leptin is synthesized & secreted by white adipose tissue and acts in the brain and peripheral tissues. People who undergo diet (eating less), their adipose cells loses fat leading to a decreased amount of leptin. Plasma leptin concentration is proportional to the adipose mass & acts by inhibiting food intake and increases energy release.