An animal defending against a predator may engage in either " fight or flight " or " tend and befriend " in response to predator attack or threat of attack, depending on its estimate of the predator's strength relative to its own. Alternative defenses include a range of antipredator adaptations , including alarm signals . An example of an alarm signal is nerol, a chemical which is found in the mandibular glands of Trigona fulviventris individuals.  Release of nerol by T. fulviventris individuals in the nest has been shown to decrease the number of individuals leaving the nest by fifty percent, as well as increasing aggressive behaviors like biting.  Alarm signals like nerol can also act as attraction signals; in T. fulviventris, individuals that have been captured by a predator may release nerol to attract nestmates, who will proceed to attack or bite the predator. 
As for “willpower” no chemical is going to give you that either, that comes from your heart, your mettle. It comes from wanting something so bad you’ll do whatever it takes to obtain it. When you want something real bad you’ll be surprised how much you wake up and get energized. If you need some “willpower” let me suggest this: Make some goals – write down your goal weight in exact numbers. If its 175lb then spell it out on papers in clear dark print. Place those papers everywhere, on you dresser, on your mirrors, hell on your forehead if you have to. Then make a plan to get to that weight. Let that plan include your diet (calories in) and your workout (calories out). At your age you’ll find that if your calories out are a couple hundred more than your calories in you will drop weight quickly; and when I say quickly give it 2-4 weeks and you should start seeing good results. IMPORTANT: This does not mean to starve yourself, you will still need to eat, in fact starving yourself may cause your body to hold onto the weight longer. I find for me dividing my daily calorie needs over 5 spread out meals works best; maybe start there. Here is a link to a tool to help guide you on how many calories you should eat a day Calorie Tool . Once you see the results you will become inspired and that inspiration will give you the “willpower” you need until that goal is met.
Involuntary weight loss is a marker of potential problems, and weight restoration is a potential solution. However, the real key diagnostic information is the status of body composition (Table 3 ). Since normal body composition for the individual of concern is not known prior to the insult, a host of normalized tables and equations, with an assumed normal value, are used. Therefore, the actual alteration of body composition caused by an insult or poor nutrition (or usually both) is not known. The complications, for example, the weakness seen in the patient, as well as the presence of a catabolic state that will lead to LBM loss, are often the best clinical markers. Of the available methods (Table 3 ), skin-fold thickness and bioelective impendence are valuable if taken sequentially over time, but some form of baseline is needed; on the other hand, nitrogen balance provides direct information as to whether the patient was catabolic or anabolic on the measurement day, and how catabolic. 22 28