Should I do reflection before eating if I don't plan to keep it

When one tries not to break ones promise, and to live life according to the well-being of others, this is a high concept of moral. Those concepts are not part of Buddhism directly, but they are derived from the inner Philosophy of mind and world. While they are certainly part of the discourses of Buddhist traditions, it should be important to notice that in Buddhism there is no doctrine -- this is if one looks at Buddhism as philosophy (close to the Pali Canon or the Theravada tradition).

What is Buddhist moral according to Buddhist philosophy then? In Buddhist philosophy, the whole worldly phenomenon as it is experienced in any moment is dukkha, 'pain' or 'suffering', or tanha, 'thirst', 'volition', 'craving'. Overcoming this whole phenomenon is the 'extinction of thirst', or tanhakkhaya, it means one is able to see 'truth', nirvana. 'Mental activity' means 'conditioning', or samkhara, and reproduces dukkha. 'Volitional action' according to Buddhist philosophy is called kamma (not to be with the Western term or the karma in the Vedas). All things that are either kusala, akusala, 'wholesome' and 'unwholesome' are reproducing, they are leading to 'rebirth', samsara, meaning they will lead the mind to more conditioned states.

To come back to your question: Doing something willingly wrong, like lying, can usually be considered more strongly unwholesome. But this is not to say that doing the opposite will save one from suffering. Wanting to do good is just another mental formation.

Loosely speaking, the margin between good and bad is thin, like with most things in the world. Our organisms need salt, but eating several spoons will damage the body severely. The closer you get to see truth, the more precise you come to describe the world as it is experienced. But for all the different states that we are in, there is a solution to come to a less conditioned state. The Fourth Noble Truth is the Noble Eightfold Path, consisting of a variety of trainings. Mainly those trainings aim at producing 'ethical conduct', 'mental discipline', and 'wisdom', sila, samadhi and panna.

This Buddhist path deals with the Right Speech, samma vaca, it is the 3rd category of the Noble Eightfold Path. (The 4th is Right Action, samma kammanta and might be related to this question also.) Speech should be useful, one can also remain silent rather than engaging in wrong speech.

As I see it, the declaration or phrase used to receive food is more of a gesture. It is a nice act, it can help to implement good habits, it acts as a little reminder. This reminder is karma in the sense of the Vedas or Hindu sense: It is a mere action. The point is that according to Buddhism the mere speech is not kamma, it is just sound. What matters more is mental volition.

The mismatch of the words and the (assumed) behavior of the person receiving the food is neither morally right nor wrong. If the mismatch helps the receiver be actually more careful in his ethical conduct one day, but it also might not do this -- the receiver also doesn't know what will come. But what is considered morally right, is the individual's effort towards a solution.

The reflection before eating is not a promise or saying something you will do. This is to gradually bend your mind and build strong resolve so you do not eat for enjoyment or other reason but to fulfil your meditation and practice and to maintain life.

If you willing do not intend to keep it it might be counterproductive in building this intention. But if you reflect and it does not go as reflected it is OK. You should strengthen you resolve next time. This might take some practice to do this to start with. A point will come when you can keep your resolve. If you're not resolve it at just recite it then this is self deception and should be avoided.

Also monks do give a morsel of food to animals before partaking meals. Perhaps you can add this to your practice also even if you are a layperson.

Even if you are layperson it is good to make a strong resolution about food and if it breaks make a stronger resolution. If you are a Novice make use of this period so you can fulfil the Vinaya after higher ordination. If you are a Monk with higher ordination make amends as prescribed in the Vinaya. Also not if you willfully break Vinaya as a higher ordinated monk this is bad Karma. You should not have self deception and you should try your best to keep it as a monk.

So my question is should one say a reflection on food ("i use this almsfood not for beautification but for supporting the holy life etc etc ...") when he knows he probably isnt going to keep it ?

As a lay person: Probably not..

As a monastic: Definitely not!

Reflecting on Alms food belongs to the The Four Requisites, namely:

"Properly considering almsfood, I use it: not playfully, nor for intoxication, nor for putting on weight, nor for beautification; but simply for the survival and continuance of this body, for ending its afflictions, for the support of the chaste life, (thinking) I will destroy old feelings (of hunger) and not create new feelings (from overeating). Thus I will maintain myself, be blameless, and live in comfort."

As explained in the footnotes/commentary - then a monk should make use of offerings properly and not do anything with them which will make the donors faith decline.

What about when he thinks theres a tiny chance he will ?

If his intentions are wholesome, then yes of course. Even a small amount of wholesome intention, serves to strengthen the Adhiṭṭhāna (resolution) pāramī.

What about most likley will keep it ?

Yes of course.

Actions that reduce distance to Nibbana should be undertaken.