and Back to Nature divestitures and an increase in interest expense. Adjusted diluted earnings per share was also negatively impacted by an increase in diluted weighted average shares outstanding.
For the fourth quarter of 2023, adjusted EBITDA was $86.8 million, a decrease of $6.8 million, or 7.3%, compared to $93.6 million for the fourth quarter of 2022. The decrease in adjusted EBITDA was primarily attributable to the Green Giant U.S. shelf-stable and Back to Nature divestitures. Adjusted EBITDA as a percentage of net sales was 15.0% for the fourth quarter of 2023, compared to 15.0% for the fourth quarter of 2022.
Financial Results for Full Year Fiscal 2023
Net sales for fiscal 2023 decreased $100.7 million, or 4.7%, to $2,062.3 million from $2,163.0 million for fiscal 2022. The decrease was primarily attributable to the Back to Nature divestiture, the Green Giant U.S. shelf-stable divestiture, and a decrease in unit volume and the negative impact of foreign currency, which were partially offset by an increase in net pricing and the impact of product mix. Net sales of Back to Nature, which the Company divested on January 3, 2023, and therefore not part of the Company’s fiscal 2023 results, were $46.3 million during fiscal 2022(2). Net sales of the Green Giant U.S. shelf-stable product line, which the Company divested on November 8, 2023, were $24.6 million lower in fiscal 2023 compared to fiscal 2022, primarily due to the divestiture.
Base business net sales for fiscal 2023 decreased $30.0 million, or 1.5%, to $1,997.2 million from $2,027.2 million for fiscal 2022. The decrease in base business net sales was driven by a decrease in unit volume of $118.2 million and the negative impact of foreign currency of $5.1 million, partially offset by an increase in net pricing and the impact of product mix of $93.3 million, or 4.6% of base business net sales.
Net sales of Clabber Girl increased $31.1 million, or 32.1%; net sales of the Company’s spices & seasonings(3) increased $8.1 million, or 2.2%; and net sales of Maple Grove Farms increased $2.4 million, or 2.9%, in fiscal 2023 as compared to fiscal 2022. Net sales of Crisco decreased $38.2 million, or 10.3%; net sales of Green Giant (including Le Sueur and excluding net sales of the Green Giant U.S. shelf-stable product line) decreased $28.7 million, or 6.6%; net sales of Ortega decreased $6.4 million, or 4.1%; and net sales of Cream of Wheat decreased $2.9 million, or 3.6%, in fiscal 2023, as compared to fiscal 2022. Base business net sales of all other brands in the aggregate increased $4.6 million, or 1.0%, for fiscal 2023, as compared to fiscal 2022.
Gross profit was $455.5 million for fiscal 2023, or 22.1% of net sales. Adjusted gross profit(1), which excludes the negative impact of $2.9 million of acquisition/divestiture-related expenses and non-recurring expenses included in cost of goods sold during fiscal 2023, was $458.4 million, or 22.2% of net sales. Gross profit was $409.6 million for fiscal 2022, or 18.9% of net sales. Adjusted gross profit, which excludes the negative impact of $9.1 million of acquisition/divestiture-related expenses and non-recurring expenses included in cost of goods sold during fiscal 2022, was $418.7 million, or 19.4% of net sales.
The improvements in gross profit and gross profit as a percentage of net sales were driven by an increase in net pricing relative to input costs as compared to fiscal 2022, the moderation of input cost inflation, lower transportation and warehousing costs, and lower depreciation expense. Beginning in the fourth quarter of 2022, the Company has realized the benefits of previously announced list price increases, which, together with additional list price increases in 2023, partially offset by certain list price decreases, contributed to the Company’s recovery in gross profit and gross profit as a percentage of net sales during fiscal 2023.
Selling, general and administrative expenses increased $5.6 million, or 3.0%, to $196.0 million for fiscal 2023 from $190.4 million for fiscal 2022. The increase was composed of increases in general and administrative expenses of $14.1 million and consumer marketing expenses of $3.1 million, partially offset by decreases in warehousing expenses of $5.3 million, selling expenses of $3.2 million and acquisition/divestiture-related and non-recurring expenses of $3.1 million. Expressed as a percentage of net sales, selling, general and administrative expenses increased by 0.7 percentage points to 9.5% for fiscal 2023, as compared to 8.8% for fiscal 2022.