It would be a very bad idea to gain weight to go on the nd. You are actually on the high side of normal bmi (see below). Metabolic syndrome kicks in at a much lower bmi than european bmi scale.
The whole point of the diet is to lose fat from the liver and pancreas this happens because you are eating less than you need. The first store of fat that is used to fuel your calorie deficit is in your liver it is there, from an evolutionary point of view, to get you up and about while fasted to search for food. The problem with a lot of people now is they never use this fat so it constantly increases fuelled by huge modern consumption of fructose, alcohol, trans fats, branch-chain amino acids etc coupled with low levels of activity which is also visceral fat burning.
http://www.ncl.ac.uk/magres/research/diabetes/reversal.htm
"Some people can tolerate a BMI of 40 or more without getting diabetes. Others cannot tolerate a BMI of 22 without diabetes appearing, as their bodies are set to function normally at a BMI of, say 19. This is especially so in people of
South Asian ethnicity."
According to your profile you have a bmi of 21.7 which if you see below the bmi measures for "asian indians" is on the higher side of normal
"BMI or Body Mass Index is a globally acknowledged, scientific method of measuring obesity. Recommended by the WHO (World Health Organization), it is a simple index of weight- for- height, which is used to classify underweight, normal, overweight and obese adults along with their level of associated health risks. It is calculated by dividing the weight in kilograms by the square of an individual’s height in meters. The classification of Underweight, Normal Overweight and Obese according to BMI is given in the table below (Ref: Misra A. Body Composition and the metabolic syndrome in Asian Indians: A saga of multiple adversities. Natl Medical J India 2003;16(1):3-7 )
Classification of adults according to BMI
Classification
Normal range
Normal
18.5 - 22.9