Studies have identified variants in several genes that may contribute to body fat distribution and ultimately weight gain and; although, only in a few cases are genes the primary cause of obesity. Candidate gene and genome-wide association studies have led to the discovery of nine loci concerned in Mendelian forms of obesity and 58 loci contributes to polygenic obesity. These loci justify a small fraction of the heritability for obesity and many genes remain to be discovered.

Poor diet is one of the major contributors to the leading causes of chronic illness and death. Healthy diets along with physical activity are key to good nutrition and necessary for a long and healthy life. Eating nutritional foods and balancing energy intake with the necessary physical activity to maintain a healthy weight is essential at all stages of life. Unbalanced intake of foods high in energy (sugar, starch and/or fat) but low in essential nutrients commits to energy excess, overweight and obesity. The quantity of the energy consumed in relevancy to physical activity and also the quality of food are key determinants of nutrition connected to chronic disease.

Being overweight or obese creates psychosocial risks for the child. Being significantly overweight has an impact on the child's level of self-esteem and creates problems in social relationships with peers subjecting them to teasing and ridicule, resulting in social withdrawal. Obese children are unable to participate in the same level of physical activity as other children. The ongoing stigma and social isolation of being different erodes the child's sense of wellbeing, and unless there is a reversal of the child's condition, serious mental health problems can ensue.

The body requires many different vitamins and minerals that are essential for both body development and prevention of a disease. These vitamins and minerals are known as micronutrients. A nutritional deficiency occurs when the body doesn’t absorb or get necessary amount of a nutrient from the food. Deficiencies can lead to a variety of health problems like digestion problems, skin disorders, stunted or defective bone growth, and even dementia.

On the other Hand, metabolism is the rate at which our body utilizes our nutrition. While there are many factors that influence our metabolism (hormone levels, enzyme secretion, chronic disease conditions, medications, stress, activity level and sleep patterns). The rate of metabolism directly effects caloric needs and results in weight loss or weight gain.

Sex steroid hormones are concerned with the metabolism, accumulation as well as the distribution of adipose tissues. Recent studies reveal that progesterone receptor, oestrogen receptor and androgen receptor exist in adipose tissues therefore, their actions could be direct. Sex steroid hormones carry out their function in adipose tissues by both nongenomic and genomic mechanisms.

Pediatric Nutrition is a description of the dietary needs of infants. In Pediatric nutrition the most important aspect is breastfeeding. Feeding the premature baby provides the long chain fatty acids and prebiotics to the children. Severely undernourished children die of insufficient management with too much volume and too much protein in the initial phase.

Childhood obesity is a condition where excess body fat has a negative impact on a child's health or well-being. Due to the rising prevalence of childhood obesity and its many adverse health effects it is being recognized as a serious public health concern. Childhood obesity can lead to diabetes, high blood pressure and cholesterol, early heart problems and skin conditions such as heat rash, fungal infections, and acne.

Several studies have found that a numbers of patients with mental illness are obese compared to the general population. Mental illness may increase the risk of obesity, while obesity may increase an individual's chances to develop a psychiatric disorder. The reasons behind the link between obesity and psychiatric problems are poor self-image, the biological disruptions caused by obesity, physical inactivity and the social stigma related to being overweight. Epidemiological studies justify positive associations between obesity and mood disorders.

Studies shows that food, aerobic exercise and sleep has an effect on the brain functioning and mental health. This raises the exciting probabilities that changes in diet can enhance cognitive abilities, protect the brain from damage and counteract the effects of aging. Excess calories reduce the flexibility of synapses and increase the chances of cell damage during the formation of free radicals.

The Primary prevention of obesity in children, young people, and adults provides information on preventing overweight and obesity by lifestyle modification program, focus on recommendations for physical activity, healthy diet along periodical medical examination. It also deals with weight management in children and adults by regular assessment based on body mass index (BMI) and to assess underlying causes, risk factors, and comorbidities of obesity. Management of obesity includes lifestyle changes, medications as well as surgery. The main treatment for obesity consists of physical activities and dieting.

Traditional Chinese medicine is a kind of traditional medicine usually based on more than 2,500 years old Chinese medical practice which includes various forms of herbal medicine, acupuncture, massage, exercise, and dietary therapy to prevent health problems. Acupuncture involves thin needles which are inserted into the body. Acupuncture is usually safe when done by properly by a trained practitioner using clean and single-used needle technique.

Yoga is among the ancient form of exercise that focuses on your mind, body and soul. On the other hand, physical therapy, not only works to prevent osteoporosis in women and neck pain or low back pain, physical therapy is a proven weight management tool. Physical therapist can perform a full assessment of body and health targeting areas of concern and customize an exercise program designed to reduce, in fact, eliminate pain and making healthier beings. Therapists can teach the correct form for each exercise to be performed with minimal pain and strain helping getting rid of the excess pounds.