diff --git a/GainStation13/code/mechanics/fatness.dm b/GainStation13/code/mechanics/fatness.dm
index b2c370571f..4315a6570a 100644
--- a/GainStation13/code/mechanics/fatness.dm
+++ b/GainStation13/code/mechanics/fatness.dm
@@ -275,3 +275,11 @@ GLOBAL_LIST_INIT(uncapped_resize_areas, list(/area/command/bridge, /area/mainten
 	var/fat_to_add = ((amount * CONFIG_GET(number/damage_multiplier)) * FAT_DAMAGE_TO_FATNESS)
 	adjust_fatness(fat_to_add, FATTENING_TYPE_WEAPON)
 	return fat_to_add
+
+/mob/living/carbon/proc/applyPermaFatnessDamage(amount)
+	if(!client?.prefs?.weight_gain_permanent) // If we cant apply permafat, apply regular fat
+		return applyFatnessDamage(amount)
+
+	var/fat_to_add = ((amount * CONFIG_GET(number/damage_multiplier)) * PERMA_FAT_DAMAGE_TO_FATNESS)
+	adjust_perma(fat_to_add, FATTENING_TYPE_WEAPON)
+	return fat_to_add
diff --git a/code/__DEFINES/combat.dm b/code/__DEFINES/combat.dm
index 4629c4a954..785c83c322 100644
--- a/code/__DEFINES/combat.dm
+++ b/code/__DEFINES/combat.dm
@@ -277,5 +277,7 @@
 
 // GS13 EDIT
 #define FAT 		"fat"
+#define PERMA_FAT 		"perma_fat"
 /// What is the rate that one damage is converted to fatness?
 #define FAT_DAMAGE_TO_FATNESS 4
+#define PERMA_FAT_DAMAGE_TO_FATNESS 4
diff --git a/code/modules/mob/living/carbon/human/species.dm b/code/modules/mob/living/carbon/human/species.dm
index 5f2875df34..550d179583 100644
--- a/code/modules/mob/living/carbon/human/species.dm
+++ b/code/modules/mob/living/carbon/human/species.dm
@@ -2325,6 +2325,8 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 		// GS13 EDIT
 		if(FAT)
 			H.applyFatnessDamage(damage * hit_percent)
+		if(PERMA_FAT)
+			H.applyPermaFatnessDamage(damage * hit_percent)
 
 	return TRUE