diff --git a/src/lib/components/diary/MacroSummary.svelte b/src/lib/components/diary/MacroSummary.svelte
index f92146c..75853f3 100644
--- a/src/lib/components/diary/MacroSummary.svelte
+++ b/src/lib/components/diary/MacroSummary.svelte
@@ -2,6 +2,7 @@
 	import type { Diary } from '$lib/types/api';
 	import { kcal, g } from '$lib/utils/format';
 	import { updateDiary } from '$lib/api/diary';
+	import { updateUserSettings } from '$lib/api/settings';
 	import { useQueryClient } from '@tanstack/svelte-query';
 	import Sheet from '$lib/components/ui/Sheet.svelte';
 
@@ -31,6 +32,8 @@
 	// Goal editing sheet
 	let sheetOpen = $state(false);
 	let saving = $state(false);
+	let syncSettingsOpen = $state(false);
+	let lastSavedForm: typeof form | null = null;
 	let form = $state<{
 		calories_goal: number | null;
 		protein_goal: number;
@@ -61,11 +64,19 @@
 		try {
 			await updateDiary(date, form);
 			await queryClient.invalidateQueries({ queryKey: ['diary', date] });
+			lastSavedForm = { ...form };
 			sheetOpen = false;
+			syncSettingsOpen = true;
 		} finally {
 			saving = false;
 		}
 	}
+
+	async function handleSyncToSettings() {
+		if (!lastSavedForm) return;
+		await updateUserSettings(lastSavedForm);
+		syncSettingsOpen = false;
+	}
 </script>
 
 <div class="bg-zinc-900 rounded-2xl p-4 relative">
@@ -125,6 +136,20 @@
 	</div>
 </div>
 
+<Sheet open={syncSettingsOpen} onclose={() => syncSettingsOpen = false} title="Update global settings?">
+	<p class="text-sm text-zinc-400 mb-5">Override your default macro goals in user settings with these values as well?</p>
+	<div class="flex gap-3">
+		<button
+			onclick={() => syncSettingsOpen = false}
+			class="flex-1 bg-zinc-800 hover:bg-zinc-700 rounded-xl py-3 text-sm font-medium transition-colors"
+		>No</button>
+		<button
+			onclick={handleSyncToSettings}
+			class="flex-1 bg-green-600 hover:bg-green-500 rounded-xl py-3 font-semibold transition-colors"
+		>Yes</button>
+	</div>
+</Sheet>
+
 <Sheet open={sheetOpen} onclose={() => sheetOpen = false} title="Day goals">
 	<form onsubmit={handleSave} class="space-y-4">
 		<!-- Calories: null = auto-calculated by server from macros -->
diff --git a/src/routes/(app)/settings/+page.svelte b/src/routes/(app)/settings/+page.svelte
index fe08990..fdaab41 100644
--- a/src/routes/(app)/settings/+page.svelte
+++ b/src/routes/(app)/settings/+page.svelte
@@ -1,7 +1,9 @@
 <script lang="ts">
 	import { createQuery, useQueryClient } from '@tanstack/svelte-query';
 	import { getUserSettings, updateUserSettings } from '$lib/api/settings';
+	import { updateDiary } from '$lib/api/diary';
 	import TopBar from '$lib/components/ui/TopBar.svelte';
+	import Sheet from '$lib/components/ui/Sheet.svelte';
 	import { today } from '$lib/utils/date';
 
 	const queryClient = useQueryClient();
@@ -15,6 +17,8 @@
 	let saving = $state(false);
 	let saved = $state(false);
 	let error = $state('');
+	let syncDiaryOpen = $state(false);
+	let lastSavedForm: typeof form | null = null;
 
 	let form = $state<{
 		calories_goal: number | null;
@@ -49,14 +53,23 @@
 		try {
 			await updateUserSettings(form);
 			queryClient.invalidateQueries({ queryKey: ['user-settings'] });
+			lastSavedForm = { ...form };
 			saved = true;
 			setTimeout(() => { saved = false; }, 2000);
+			syncDiaryOpen = true;
 		} catch {
 			error = 'Failed to save settings';
 		} finally {
 			saving = false;
 		}
 	}
+
+	async function handleSyncToDiary() {
+		if (!lastSavedForm) return;
+		await updateDiary(today(), lastSavedForm);
+		queryClient.invalidateQueries({ queryKey: ['diary', today()] });
+		syncDiaryOpen = false;
+	}
 </script>
 
 <div class="flex flex-col h-screen">
@@ -139,3 +152,17 @@
 		{/if}
 	</main>
 </div>
+
+<Sheet open={syncDiaryOpen} onclose={() => syncDiaryOpen = false} title="Update today's diary?">
+	<p class="text-sm text-zinc-400 mb-5">Override today's diary macro goals with these values as well?</p>
+	<div class="flex gap-3">
+		<button
+			onclick={() => syncDiaryOpen = false}
+			class="flex-1 bg-zinc-800 hover:bg-zinc-700 rounded-xl py-3 text-sm font-medium transition-colors"
+		>No</button>
+		<button
+			onclick={handleSyncToDiary}
+			class="flex-1 bg-green-600 hover:bg-green-500 rounded-xl py-3 font-semibold transition-colors"
+		>Yes</button>
+	</div>
+</Sheet>