There are various ways to lose 15 kgs in 55 days. The best option is regulating your diet while taking relevant exercises.
Diet.
How to lose 7 kg in 2 weeks
less than 3 kg to lose your weight
It is not possible to lose 30 kg in 30 days and remain healthy. To lose that amount of weight safely, would take at least a year.
It depends on the diet one is taking. It takes about 1 month to lose 5 kg.
With great difficulty and a really, really strict diet.
There isn't a miracle diet plan that will help a person go from a total of 76 kg down to 70 kg. It is important to eat right and exercise in order to lose weight over time.
No. However, if you drink a gallon of water, juice or soda in a short period of time and then weigh yourself, you will have gained 4 kg. Just about all of that will be excreted through the urine. So, in this kind of scenario, it would not be unusual to lose 4 kg in two days.
if you have balanced diet and exercise eventually in a few months
You can't - even if you starve yourself (which is dangerous) you could not lose that much weight in 7 days.
You can reportedly lose up to 20 kg in 2 weeks by following the Swedish diet. This diet incorporates three specific small meals each day and you must drink two liters of water daily.