replace numbers by define like harry told me.

code/__DEFINES/chemistry.dm

@@ -49,6 +49,7 @@
 
 // Nutrition levels
 #define NUTRITION_MAX 550
+#define NUTRITION_HIGH 540
 #define NUTRITION_NORMAL 400
 #define NUTRITION_LOW 250
 #define NUTRITION_VERYLOW 50

code/game/objects/items/reagent_containers/food/snacks.dm

@@ -60,7 +60,7 @@
 	if(istype(M, /mob/living/carbon))
 		var/mob/living/carbon/C = M
 		var/fullness = M.nutrition + (M.reagents.get_reagent_amount("nutriment") * 25)
-		if(fullness > 540 && world.time < C.overeat_cooldown)
+		if(fullness > NUTRITION_HIGH && world.time < C.overeat_cooldown)
 			to_chat(user, SPAN_WARNING("[user == M ? "You" : "They"] don't feel like eating more right now."))
 			return
 		if(issynth(C))
@@ -70,22 +70,22 @@
 			to_chat(user, SPAN_DANGER("[user == M ? "You are" : "[M] is"] unable to eat!"))
 			return
 
-		if(fullness > 540)
+		if(fullness > NUTRITION_HIGH)
 			C.overeat_cooldown = world.time + OVEREAT_TIME
 
 		if(M == user)//If you're eating it yourself
-			if (fullness <= 50)
+			if (fullness <= NUTRITION_VERYLOW)
 				to_chat(M, SPAN_WARNING("You hungrily chew out a piece of [src] and gobble it!"))
-			if (fullness > 50 && fullness <= 150)
+			if (fullness > NUTRITION_VERYLOW && fullness <= NUTRITION_LOW)
 				to_chat(M, SPAN_NOTICE(" You hungrily begin to eat [src]."))
-			if (fullness > 150 && fullness <= 350)
+			if (fullness > NUTRITION_LOW && fullness <= NUTRITION_NORMAL)
 				to_chat(M, SPAN_NOTICE(" You take a bite of [src]."))
-			if (fullness > 350 && fullness <= 540)
+			if (fullness > NUTRITION_NORMAL && fullness <= NUTRITION_HIGH)
 				to_chat(M, SPAN_NOTICE(" You unwillingly chew a bit of [src]."))
-			if (fullness > 540)
+			if (fullness > NUTRITION_HIGH)
 				to_chat(M, SPAN_WARNING("You reluctantly force more of [src] to go down your throat."))
 		else
-			if (fullness <= 540)
+			if (fullness <= NUTRITION_HIGH)
 				user.affected_message(M,
 					SPAN_HELPFUL("You <b>start feeding</b> [user == M ? "yourself" : "[M]"] <b>[src]</b>."),
 					SPAN_HELPFUL("[user] <b>starts feeding</b> you <b>[src]</b>."),

code/game/objects/items/tools/kitchen_tools.dm

@@ -46,7 +46,7 @@
 
 	if (reagents.total_volume > 0)
 		var/fullness = M.nutrition + (M.reagents.get_reagent_amount("nutriment") * 25)
-		if(fullness > 540)
+		if(fullness > NUTRITION_HIGH)
 			to_chat(user, SPAN_WARNING("[user == M ? "You" : "They"] don't feel like eating more right now."))
 			return ..()
 		reagents.set_source_mob(user)