According to studies, the risk of cerebrovascular disease and cognitive decline are associated with age-related changes. In addition, there is data suggesting a relationship between the progression of this pathology and the presence of obesity and associated metabolic disorders. According to to some research, weight loss associated with cognitive function decline. In this regard, the development of effective, applicable in real clinical practice methods of non-drug treatment and prevention of cerebrovascular disorders and age-related cognitive decline in people with obesity and metabolic disorders, who are at high risk, seems to be extremely relevant.

The main goal of the study is to compare the effectiveness of various weight loss approaches and to study their effects on the cognitive functions of elderly obesity women.

The high prevalence of comorbid pathology characterised the elderly and senile population. Particularly, comorbid condition is often based on obesity. Also, an important characteristic of the elderly and senile age is the development of age-related cognitive deficit and progressive decline in cognitive functions, that is detected in 60.8% of people over 65 years old in Russia according to the EVKALIPT study.

The prevalence of obesity in the Russian population reaches 40% among the elderly population. According to studies, the presence of obesity is "paradoxically" associated with less progression of cognitive function loss, and the risk reduction in some populations reaches 40%. However, the sarcopenic obesity is an independent predictor of cognitive impairment in the elderly. Consequently, the therapy of obesity in elderly and senile population faces two important aspects: the risk of muscle loss and the development of sarcopenia and progressive cognitive decline. The described features of this age group are consistent with the well-known "obesity paradox", in which overweight and obesity are associated with longer life expectancy.

The risk of muscle mass reduction and cognitive functions decrease determines the formation of a specialised approach to obesity management in older population. Thus, the setting of softer and longer-term goals with a gradual decrease in body weight is typical. Studies have considered the use of various interventions, so far the combination of diet with exercise has proven effectiveness in muscle mass protection. At the same time, regular exercises reliably protect from cognitive decline. Thereby, the combination of diet and physical activity is considered as a suitable approach to obesity management in the elderly.

Recently, there have also been a number of studies evaluating the effectiveness of the ketogenic diet. This diet pattern is reliably effective in body weight reduction, skeletal muscle mass maintenance, and adipose tissue metabolism improvement in the elderly . Also, the neuroprotective effects of the ketogenic diet have been confirmed by meta-analyses and have made it possible to include it in current guidelines for the prevention and treatment of cognitive impairment. However, the high frequency of negative effects and the associated low adherence limit the possibilities of using this diet, which led to the development of exogenous ketones that allow reaching the levels of blood ketone bodies associated with neuroprotective properties (0.2-0.5 mmol/l) with better portability.

The main goal of the study is to compare the effectiveness of various weight loss approaches and to study their effects on the cognitive functions of elderly obesity women.

Inclusion Criteria:

1. Female;
2. Age 60 and over;
3. BMI 30.0 kg/m2 or more.

Exclusion Criteria:

1. Male;
2. age under 60;
3. BMI <30.0 kg/m2;
4. patients unable or unwilling to comply with the requirements of the protocol, including the signing of informed consent (inability to give such consent due to mental deficiency or language barrier), as well as non-compliance with the schedule of visits, persons unable to independently make a decision and sign an informed consent;
5. less than 6 months after suffering cardiovascular events, stroke, severe surgical interventions and injuries;
6. alcohol abuse (including chronic pancreatitis of alcoholic etiology) or drug addiction at present or within the last 5 years;
7. history of malignant diseases, regardless of the treatment during the last 5 years;
8. less than 4 weeks after suffering acute infectious and / or inflammatory diseases, after the onset of complete clinical and laboratory remission;
9. pregnancy and lactation;
10. history of allergic reactions to components of the study product and/or placebo or intolerance to components of the study product and/or placebo.

The females participants are reqruited In order to reduce variability of results in the restricted sample size (40 person per group).

Masking is used between 2 groups out of 5 (between the Product group and Placebo group). The investigated product and Placebo have comparable organoleptic properties and are packed in the same containers labelled as N1 or N2.

The participants are randomised for 5 arms. In the case of arms 1 and 2, they are prescribed to consume 2 doses of product per day without awareness of either it is the investigational product or a placebo (the investigational product or a placebo). Field investigators prescribe to participants product N1 or N2 according to group allocation without awareness of either it is the investigational product or a placebo.