diff --git a/GainStation13/code/mechanics/fatness.dm b/GainStation13/code/mechanics/fatness.dm
index 5d6cc33f..fa6d0040 100644
--- a/GainStation13/code/mechanics/fatness.dm
+++ b/GainStation13/code/mechanics/fatness.dm
@@ -96,6 +96,10 @@
 			if(!client?.prefs?.weight_gain_viruses)
 				return FALSE
 
+		if(FATTENING_TYPE_NANITES)
+			if(!client?.prefs?.weight_gain_nanites)
+				return FALSE
+
 		if(FATTENING_TYPE_WEIGHT_LOSS)
 			if(HAS_TRAIT(src, TRAIT_WEIGHT_LOSS_IMMUNE))
 				return FALSE
diff --git a/GainStation13/code/modules/client/preferences/preferences.dm b/GainStation13/code/modules/client/preferences/preferences.dm
index 3a3e920c..1175fde5 100644
--- a/GainStation13/code/modules/client/preferences/preferences.dm
+++ b/GainStation13/code/modules/client/preferences/preferences.dm
@@ -13,6 +13,8 @@
 	var/weight_gain_magic = FALSE
 	///Weight gain from viruses
 	var/weight_gain_viruses = FALSE
+	///Weight gain from nanites
+	var/weight_gain_nanites = FALSE
 	///Blueberry Inflation
 	var/blueberry_inflation = FALSE
 	///Extreme weight gain
diff --git a/code/__DEFINES/misc.dm b/code/__DEFINES/misc.dm
index d51813ec..5ea0dada 100644
--- a/code/__DEFINES/misc.dm
+++ b/code/__DEFINES/misc.dm
@@ -527,6 +527,7 @@ GLOBAL_LIST_INIT(lighter_reskins, list(ZIPPO_SKIN_PLAIN = "plain", ZIPPO_SKIN_DA
 #define FATTENING_TYPE_WEAPON "weapon"
 #define FATTENING_TYPE_MAGIC "magic"
 #define FATTENING_TYPE_VIRUS "virus"
-#define FATTENING_TYPE_WEIGHT_LOSS "weight_loss" 
+#define FATTENING_TYPE_NANITES "nanites"
+#define FATTENING_TYPE_WEIGHT_LOSS "weight_loss"
 
 #define FATNESS_TO_WEIGHT_RATIO 0.25
diff --git a/code/modules/client/preferences.dm b/code/modules/client/preferences.dm
index a33d2a3c..b2e83199 100644
--- a/code/modules/client/preferences.dm
+++ b/code/modules/client/preferences.dm
@@ -1063,6 +1063,7 @@ GLOBAL_LIST_EMPTY(preferences_datums)
 			dat += "<b>Weight Gain - Weapons:</b><a href='?_src_=prefs;preference=weight_gain_weapons'>[weight_gain_weapons == TRUE ? "Enabled" : "Disabled"]</a><BR>"
 			dat += "<b>Weight Gain - Magic:</b><a href='?_src_=prefs;preference=weight_gain_magic'>[weight_gain_magic == TRUE ? "Enabled" : "Disabled"]</a><BR>"
 			dat += "<b>Weight Gain - Viruses:</b><a href='?_src_=prefs;preference=weight_gain_viruses'>[weight_gain_viruses == TRUE ? "Enabled" : "Disabled"]</a><BR>"
+			dat += "<b>Weight Gain - Nanites:</b><a href='?_src_=prefs;preference=weight_gain_nanites'>[weight_gain_nanites == TRUE ? "Enabled" : "Disabled"]</a><BR>"
 			dat += "<b>Blueberry Inflation:</b><a href='?_src_=prefs;preference=blueberry_inflation'>[blueberry_inflation == TRUE ? "Enabled" : "Disabled"]</a><BR>"
 
 			dat += "<h2>GS13 Gameplay Preferences</h2>"
@@ -2636,6 +2637,8 @@ GLOBAL_LIST_EMPTY(preferences_datums)
 					weight_gain_magic = !weight_gain_magic
 				if("weight_gain_viruses")
 					weight_gain_viruses = !weight_gain_viruses
+				if("weight_gain_nanites")
+					weight_gain_nanites = !weight_gain_nanites
 				if("weight_gain_extreme")
 					weight_gain_extreme = !weight_gain_extreme
 				if("noncon_weight_gain")
diff --git a/code/modules/client/preferences_savefile.dm b/code/modules/client/preferences_savefile.dm
index 4e272785..959b10a9 100644
--- a/code/modules/client/preferences_savefile.dm
+++ b/code/modules/client/preferences_savefile.dm
@@ -152,6 +152,7 @@ SAVEFILE UPDATING/VERSIONING - 'Simplified', or rather, more coder-friendly ~Car
 	S["weight_gain_items"] >> weight_gain_items
 	S["weight_gain_magic"] >> weight_gain_magic
 	S["weight_gain_viruses"] >> weight_gain_viruses
+	S["weight_gain_nanites"] >> weight_gain_nanites
 	S["weight_gain_weapons"] >> weight_gain_weapons
 	S["weight_gain_extreme"] >> weight_gain_extreme
 	S["wg_rate"] >> wg_rate
@@ -293,6 +294,7 @@ SAVEFILE UPDATING/VERSIONING - 'Simplified', or rather, more coder-friendly ~Car
 	WRITE_FILE(S["weight_gain_items"], weight_gain_items)
 	WRITE_FILE(S["weight_gain_magic"], weight_gain_magic)
 	WRITE_FILE(S["weight_gain_viruses"], weight_gain_viruses)
+	WRITE_FILE(S["weight_gain_nanites"], weight_gain_nanites)
 	WRITE_FILE(S["weight_gain_chems"], weight_gain_chems)
 	WRITE_FILE(S["weight_gain_weapons"], weight_gain_weapons)
 	WRITE_FILE(S["weight_gain_extreme"], weight_gain_extreme)